Weather Communications Codes A Breathless Overview by Hugh Stegman NV6H Sources are many, but mostly: World Meteorological Organization http://www.wmo.ch/ National Oceanic and Atmospheric Agency http://www.nws.noaa.gov/ 0. Why Weather Reporting Codes? =============================== In a word, clarity. Weather observation codes are very similar from one country to another, facilitating the exchange of information despite the Babel of languages, measurement units, and time zones. Meteorological groups meet regularly to deal with these issues. The resulting codes are appropriate to the type of information being exchanged. They also provide well-documented national practice exceptions such as the use of inches, feet, and miles for pressure, clouds, and visibility in United States aviation weather. In another word, brevity. When these codes were invented, back in the age of mechanical teleprinters, 50 WPM wasn't bad and 75 was screaming. There was no alternative to compact coding systems, if weather wires were to move a whole world's information in anything approaching a timely manner. After all, nothing's older than yesterday's weather forecast. Extreme brevity is no longer as important in an age of real- time binary observations being plotted in 3 dimensions on wide- area networked computer screens, but standardization is. Standards are currently maintained by the World Meteorological Organization, a UN body in Geneva with over 150 members. Changes are periodically agreed on and codified in the canonic WMO Handbook No. 306, available from the WMO web site. (Be ready to pay in Swiss francs.) Most current issues in the text-based communications have to do with the very gradual changeover from the practices of different countries into the more standard WMO formats. These changes are minor. In the US, for example, the two big ones are the switch to Celsius in reporting airport temperatures and dewpoints, and a gradual change from one bulletin heading syntax to another. 1. Weather Bulletin Structure ============================= Most of the world's thousands of different weather reports use a standard format. The United States is adopting this, however slowly, for its 6000+ products. Here's an example of the kind of thing one will copy on utility radio stations. Landlines (the "weather wire" aka the "big wire") and computer servers use very similar structures: ZCZC SAUS80 KWBC 011200 RRC METAR KDAL 011150Z 00000KT SKC 14/11 A3010 RMK 10170 20133= [more lines of data] NNNN Item One : START SIGNAL ----------------------- In this example: ZCZC Some standard starting signal such as a Telex code, ASCII string, or whatever is used by the particular network. Item Two: STANDARD INTERNATIONAL HEADER (in WMO format) ------------------------------------------------------- In this example: SAUS80 KWBC 011200 RRC The header identifies the type of product, and to whom it applies. Syntax: TTLLii CCCC DDHHMM (BBB), where TT=Type, LL=Location, ii=Number, CCCC=Collection center ID, DDHHMM = date/time group of day/hour/minute, and (BBB) is an extra information string not always used. These headers contain a great deal of information in their compact text strings, with many characters pointing into the infamous "WMO tables" of very highly organized information on just about every weather possibility anywhere in the world. There are a number of computer programs, and even web sites, that allow the decoding of these headers. One drops the header into a text box and gets back several lines of information. A useful decoder of this type is at the US National Weather Service site. The URL is: http://www.nws.noaa.gov/oso/hdecode.shtml. Sometimes US bulletins have a slightly different header, either by itself or next to the WMO format. This is the notorious "AFOS PIL," formerly the standard wire ID for all US weather product. AFOS is the Automated Field Operations and Services network used since 1982, currently being phased out for AWIPS, the Advanced Weather Interactive Processing System. AFOS uses an older ID number called the PIL for "Product Inventory Lookup," but all AWIPS communications will use either the WMO style or both. Item 3: Text ------------ The content of the bulletin. In our example: METAR KDAL 011150Z 00000KT SKC 14/11 A3010 RMK 10170 20133= [.] METAR is a code specifier, indicating that the following lines of data will be in the METeorological observation, Aviation, Routine format, as currently set forth in WMO standard code FM 15- IX, Extended. This is a very common single-line format for hourly aviation reports. If more timely information needs to be passed it's done in the similarly structured SPECI (SPECIal weather change notice, WMO FM-16). There are also standards for TEMPO (TEMPOrary), and TAF (Terminal Aerodrome Forecast). For example, FTUS in a header always means a standard set of TAF. Since METARs use a lot of plain text, it's easy to decode them in your head. In fact, their expansion into ordinary language provides much of the ATIS (Automated Terminal Information System) and VOLMET ("Flying Weather") transmissions we hear. They can also be automatically stored on web sites that provide weather information for pilots, and expanded when looked up. For a start, KDAL is the 4-letter ICAO international airport identifier (for Love Field, Dallas, TX). The next two groups are a date/time stamp and a wind direction/speed, followed by a number of observations that change with type of weather station and country. Finally there's an optional RMK (ReMarKs) field followed by the appropriate codes for things like storm activity, dust, snow, and such. The = at the end of the METAR is a terminator, corresponding roughly to the old CW BT (short-break) signal. The key word in METAR is Routine. Significant, non-routine, weather features that affect aviation will be passed in numbered warnings called SIGMET, for SIGnificant METeorological. It the US, these are divided into convective SIGMETs (thunderstorms, tornadoes) and non-convective SIGMETs (turbulence, icing, etc.). Along with all these aviation formats, we will also see surface synoptic observations in their own codes. These will be designated as AAXX or SYNOP (land synoptic code, WMO FM-12), and BBXX or SHIP (ship synoptic code, WMO FM-13) Moored weather buoys can be treated as stationary ships. Drifting ones, or those with special observations, have a BUOY code (SSVX, WMO FM-18X , replaces DRIFTER) for them. We'll have way more about all these codes. Item 4: End-Of-Message signal ----------------------------- A standard ending signal such as the NNNN in our example. 2. Special Weather Identifiers ============================== Weather stations use three different types of identifiers. One is the numeric WMO form that we see in some data fields. These can be looked up in a list available online or from WMO as a loose-leaf publication that is updated frequently by subscription. The list is hundreds of pages long in ASCII text, unfortunately, so it is not reproduced here. Another is the radio callsign, which we typically see only for Volunteer Observation System (VOS) "ships of opportunity," which have agreed to put certain standard instruments aboard and train one or more crew members in their proper use. The Beaufort wind arrows and sky condition reports shown on oceanic weather charts are usually labeled with these callsigns, as are their synoptic reports in SHIP code. Sometimes a hurricane warning or other advisory will also show the callsign of a VOS ship whose report has been used. These are the only times, typically, that radio calls appear in a weather product. WMO maintains a database of those callsigns. A semicolon-delimited record dump from 1999 is available on their web site, or a subscription can be purchased for more timely data. More important for our uses, though, are the 4-letter identifiers that show in the CCCC field of bulletin headings, or in the source field of many coded observations. These look like radio callsigns, but they are international IDs that happen to mimic the ICAO 4-letter airport convention, and in fact actually use it in the case of civilian airport METARs. However, many of these identifiers can also refer to central weather offices, information collection and relay points, or even automated instruments in the field. CONUS airports form the 4-character ICAO ID by prepending K to the three-letter IATA identifiers we're used to seeing on our baggage. Alaskan IDs begin with PA, Hawaiian with PH, and Puerto Rico with TJ. The actual callsigns of the transmitters subsequently used to pass information from this system will vary. Many US military broadcasts are in fact completely unidentified except for the product sources in the headers, which have nothing to do with who ultimately broadcasts the information. US military transmitters are usually at Elkhart, NE, near Offutt Air Force Base; Saddlebunch Key, near the Key West Naval Communication Station; Roosevelt Roads, the US Navy base in Puerto Rico. Schedules change almost weekly, as all remaining US military HF weather transmissions are by request from the fleet or the Air Force. Here are some commonly seen identifiers: ID Country/Agency Office ---- --------------- ---------------------------------------- AMMC Australia Bureau Of Meteorology, Brisbane BABJ China Beijing CWAO Canada Canadian Met. Centre, CN CWEG Canada Alberta Weather Centre, AB CYYZ Canada Toronto Weather Centre, ON EBBR Belgium Brussels EDZW Germany Met. Communications Office EGRR UK British Met. Office, Bracknell, GB EHAM Netherlands Amsterdam EKMI Denmark Met. Institute FABL South Africa Bloemfontein FAJS South Africa Johannesburg FAPR South Africa Pretoria KAWN US Air Force Aviation Weather Network, Offutt AFB, NE KGWC US Air Force Global Weather Center, Offutt AFB, NE KKCI NWS/NCEP Aviation Weather Center, Kansas City, MO KMKC NWS/NCEP SIGMET Center, Kansas City, MO KNGU US Navy US Navy Weather Center, Norfolk, VA KNHC NOAA/NWS/NCEP National Hurricane Center, Tropical Prediction Center, FL KWBC NWS/NCEP NWS Central Operations, MD KWBx NCEP Output from NWS models, per table below KWNC NWS/NCEP Climate Prediction Center KWNO NWS/NCEP Aviation Weather Center, Kansas City, MO KWNS NWS/NCEP Storm Prediction Center LEMM Spain Met. Communication Center, Madrid LFPW Meteo France Met. Center, Toulouse LIIB Italy Met. Communication Center, Rome LIMC Italy Milan LOWM Austria TAF, Surface Observations MMGL Mexico Guadalajara/Miguel Hidalgo y Costilla Int'l (See Mexican METAR sources below) MMMD Mexico Merida/Lic. Manuel Crecencio Rejon Int'l MMMX Mexico Mexico/Lic. Benito Juarez Int'l MMMZ Mexico Mazatlan/General Rafael Beulna Int'l MNMG Nicaragua Managua, Surface Observations MPTO Panama Tocumen, Surface Observations MYNN Bahamas Nassau METAR, Bahamas NZKL New Zealand Metservice Wellington, NZ NZWN New Zealand Wellington PAFA NWS/NCEP Fairbanks, AK PAJN NWS/NCEP Juneau, AK PANC NWS/NCEP Anchorage, AK PHNL NWS/NCEP Honolulu, HI RJAA Japan New Tokyo Airport RJTD Japan Japanese Met. Agency, Tokyo RPLL Philippines Aquino International Airport RUMS Russia Moscow SABM Argentina Natl. Met. Office, Buenos Aires SBBR Brazil INMET, Brasilia Airport TJSJ NWS/NCEP Puerto Rico TJNR US Navy Roosevelt Roads Naval Station, PR TTPP Trinadad&Tobago Caribbean METAR VTBB Thailand Bangkok METAR YBBN Australia Airport Met. Office, Brisbane YMMC Australia Met. Centre, Melbourne In KWBx, (x) can be: C = NCEP AVN and all other products not listed below D = Eta/Early Eta E = ETA/mesoEta F = Nested Grid Model G = Rapid Update Cycle H = Medium Range Forecast Model I = Sea Surface Temperature Analysis J = Wind/Wave model K = ENS/Global Ensemble FCST L = ENS/Regional Ensemble FCST M = Ocean Analysis Models N = Ocean Forecast Models O = Merge of Models Z = NCEP "tiles" from models Mexican METAR sources are as follows: SAMX41 MMMX METAR MMAA - Acapulco/General Juan N. Alvarez Int'l MMBT - Bahias Dehuatulco MMCB - Cuernavaca MMMX - Mexcio/Lic. Benito Juarez Int'l MMOX - Oaxaca MMPA - Poza Rica MMPB - Puebla MMPS - Puerto Escondido MMQT - Queretaro MMTL - Tulancingo MMTM - Tampico/General Francisco Javier Mina Int'l MMTO - Toluca/Lic. Adolfo Lopez M. MMVR - Veracruz/General Heriberto Jara Int'l MMZH - Zihuatanejo SAMX42 MMGL METAR MMAS - Aguascalientes MMEP - Tepic MMGL - Guadalajara/Miguel Hidalgo y Costilla Int'l MMIA - Colima MMLO - Del Bajio/Int'l Guanajuato MMMM - Morelia MMPN - Uruapan MMPR - Puerto Vallarta/Lic. Gustavo Dias Ordaz Int'l MMSP - San Luis Potosi MMZC - Zactecas MMZO - Manzanillo Int'l SAMX43 MMMZ METAR MMCL - Culiacan MMCN - Ciudad Obregon MMDO - Durango MMGM - Guaymas/General Jose Maria Yanez Int'l MMHO - Hermosillo/Int'l MMLM - Los Mochis MMLP - La Paz/General Manuel Marquez de Leon Int'l MMLT - Loreto Int'l MMML - Mexicali/General Rodolfo Sanchez Taboada Int'l MMMZ - Mazatlan/General Rafael Beulna Int'l MMSD - San Jose del Cabo Int'l MMTJ - Tijuana/General Abelardo L. Rodriguez Int'l SAMX44 MMMD METAR MMCE - Ciudad del Carmen MMCM - Chetumal Int'l MMCP - Campeche MMCZ - Cozumel/Int'l MMMD - Merida/Lic. Manuel Crecencio Rejon Int'l MMMT - Minatitlan MMTG - Tuxtla Gutierrez (mil) MMTP - Tapachula Int'l MMUN - Cancun Int'l MMVA - Villahermosa SAMX45 MMMY METAR MMAN - Monterrey Int/Aeropuerto del Norte MMCS - Ciudad Juarez/Abraham Gonzales Int'l MMCU - Chihuahua/Int'l MMCV - Ciudad Victoria MMIO - Satillo MMMA - Matamoros/Int'l MMMY - Monterrey/General Marianao Escobedo Int'l MMNL - Nuevo Laredo Int'l MMRX - Reynosa/Genral Lucio Blanco Int'l MMTC - Torreon Int'l. 3. A Few North American Military Weather Frequencies ==================================================== Most frequencies are assigned channel center. The dial/window frequency for FAX is usually 1.9 kHz lower, as we tune it in USB. RTTY can vary as much as 2 kHz either way, depending on receiver and habits of the operator. RTTY is 850 Hz shift, 75 baud, ITA2 Baudot code. FAX is 120 lines per minute, with an Index Of Cooperation of 576. The US Air Force transmissions are not necessarily parallel, and not all frequencies are in use at all times. This list is far from exhaustive, and frequencies change a couple of times in the average year. Consult Internet and published lists for more recent data. 3231.0 KAWN RTTY (Tune in LSB) 3131.0 KGWC FAX (Tune in USB) 4271.4 CFH FAX (Canadian Forces, Halifax; also RTTY) 4855.0 KGWC FAX 6496.4 CFH FAX (Canadian Forces, Halifax; also RTTY) 7398.0 KGWC FAX 7784.0 KAWN RTTY 7870.0 KGWC FAX 10536.0 CFH FAX (Canadian Forces, Halifax; also RTTY) 11120.0 KAWN RTTY (Tune in LSB) 11120.0 KGWC FAX (Tune in USB) 13510.0 CFH FAX (Canadian Forces, Halifax; also RTTY) 13530.0 KAWN RTTY 15781.0 KGWC FAX 19324.5 KAWN RTTY 19363.0 KGWC FAX 19530.0 KAWN RTTY (Usually "fox" marker) 4. "Old" Bulletin Type Codes ============================ These use the first two letters TT in the group TTLLii at the beginning of the heading. These provide a quick indication most of the time, but WMO has subsequently adopted a far more detailed system which we will see in the appendices to this document. Syntax: TTLL, where: TT Explanation ====== =========== AB Weather summaries AC Convective outlooks AS Surface analyses AU Upper level analyses AX Tropical discussions CS Climatic data CU Upper air climatic data FA Area forecasts FB Aviation forecasts FC Recovery forecasts FD Winds aloft forecasts FE Extended forecasts FK Air stagnation forecasts FO Model output forecasts FP Public forecasts FQ Metropolitan forecasts FS Surface forecasts FT Terminal forecasts FU Upper level forecasts FV Avalanche forecasts FW Recreational forecasts FX Prog discussions FZ Marine forecasts NF Special notices NO General notices RW River conditions, flood info and forecasts SA Surface observations SD Radar observations SE Earthquake observations SF Sferics weather data SH Synoptic ship reports SI Intermediate synoptic reports SM Synoptic observations SP Special reports SR River and rainfall observations SS Ship reports ST Ice reports SX Miscellaneous observations TB Satellite data UA Pilot reports UC,UE,UF Upper air data from ships UG,UH,UI Pibal/Rawinsonde data UJ,UK,UM Radiosonde data UN,UQ Radiosonde data UP Pibal/Rawinsonde data UR Aircraft reconnaissance data US,UW,UX Radiosonde data UT Aircraft reports UY,UZ Upper air data WF Tornado warnings WO Tropical depression advisories WR Flash flood warnings WS Sigmets WT Tropical storm/hurricane advisories WU Severe thunderstorm warnings WW Special weather statements and weather watches 5. WMO Heading Regional Codes These are used in most bulletin headings in the LL or AA part of the TTLLii / TTAAii group. LL Region == ====== AB Albania AG Argentina AH Afghanistan AI Ascension Island AJ Azerbaijan, Republic of AK Alaska AL Algeria AN Angola AT Antigua, St. Kitts & British islands in the vicinity AU Australia AY Armenia. Republic of AZ Azores Islands BA Bahamas BC Botswana BD Brunei Darussalam BE Bermuda BG Bosnia & Herzegovina BH Belize BI Burundi BJ Benin BK Banks Islands BM Myanmar (Burma) BN Bahrain BO Bolivia BR Barbados BU Bulgaria BV Bouvet Island BW Bangladesh BX Belgium, Luxembourg BY Belarus, Republic of BZ Brazil CD Chad CE Central African Rep CG Congo CH Chile CI China CM Cameroon CN Canada CR Canary Islands (Spain) CS Costa Rica CT Canton Island CU Cuba CV Cape Verde Islands CY Cyprus CZ Czech Republic DJ Djibouti DL Germany DN Denmark DO Dominica DR Dominican Republic DY Democratic Yemen EG Egypt EO Estonia EQ Ecuador ER United Arab Emirates ES El Salvador ET Ethiopia FA Faeroes Islands FG French Guyana FI Finland FJ Fiji Islands FK Falkland Isl. (Malvinas) FP Saint Pierre Island & Miquelon FR France FW Wallis and Futuna Isl. GB Gambia GC Cayman Islands GD Grenada GE Gough Island GG Georgia, Republic of GH Ghana GI Gibraltar GL Greenland GM Guam Island GN Guinea GO Gabon GQ Equatorial Guinea GR Greece GU Guatemala GW Guinea-Bissau GY Guyana HA Haiti HE St. Helena Island HK Hong Kong HO Honduras HU Hungary HV Burkina Faso HW Hawaiian Islands IC Comoros ID Indonesia IE Ireland IL Iceland IN India IQ Iraq IR Iran IS Israel IV Cote d'Lvoire IY Italy JD Jordan JM Jamaica JP Japan KA Caroline Islands KB Kiribati KG Kirgiristan, Republic of KI Christmas Islands KK Cocos Islands KN Kenya KO Korea, Republic of KP Cambodia KR Democratic People's Republic of Korea KU Cook Island KW Kuwait KY Kyrghyzstan, Republic of KZ Kazakhstan,Republic of LA Lao People's Democratic Rep LB Lebanon LC Saint Lucia LI Liberia LJ Slovenia LN Southern Line Islands LS Lesotho LT Lithuania LV Latvia LY Libyan Arab Jamahiriya MA Mauritius MB Marion Island MC Morocco MD Madeira Island MF Saint-Martin, Saint-Bartholomew, Guadeloupe, etc MG Madagascar MH Marshall Islands MI Mali MJ Former Yugoslav Rep. of Macedonia ML Malta MN St.Maarten, St.Eustatius & Saba MO Mongolia MR Martinique Island MS Malaysia MT Mauritania MU Macao MV Maldives Islands MW Malawi MX Mexico MY Mariana Islands MZ Mozambique NC New Caledonia Island NG Papua New Guinea NI Nigeria NK Nicaragua NL Netherlands NM Namibia NO Norway NP Nepal NR Niger NU Netherlands Antilles (Aruba, Bonaire, Curacao) NV Vanuatu NW Nauru Island NZ New Zealand OM Oman OR South Orkney Islands OS Austria PF French Polynesia Islands PH Philippines PI Phoenix Islands PK Pakistan PL Poland PM Panama PO Portugal PR Peru PT Pitcairn Island PU Puerto Rico PY Paraguay QT Qatar RA Russia, Republic of (East) RE Reunion and assoc. islands RH Croatia RM Republic of Moldova RO Romania RS Russia, Republic of (West) RW Rwanda SB Sri Lanka SC Seychelles Islands SD Saudi Arabia SG Senegal SI Somalia SK Sarawak SL Sierra Leone SM Suriname SN Sweden SO Solomon Islands SP Spain SQ Slovakia SR Singapore SU Sudan SV Swaziland SW Switzerland SX Santa Cruz Island SY Syria SZ Spitzbergen Islands TC Tristan da Cunha TD Trinidad and Tobago TG Togo TH Thailand TI Turks and Caicos Islands TK Tokelau Islands TM Timor TN Tanzania, United Rep of TO Tonga TP Sao Tome and Principe TR Turkmenistan, Republic of TS Tunisia TU Turkey TV Tuvalu TZ Tajikistan, Republic of UG Uganda UK United Kingdom of Great Britain and Northern Ireland UR Ukraine, Republic of US United States of America UY Uruguay UZ Uzbekistan, Republic of VG St. Vincent and the Grenadines VI Virgin Islands VN Venezuela VS Vietnam YE Yemen YG Yugoslavia ZA South Africa ZB Zambia ZM Western Samoa ZR Zaire ZS American Samoa ZW Zimbabwe 6. Full List Of Weather Codes ============================= Text-Based Codes ---------------- Text-based codes pass data as letters and numbers (alphanumerics), as opposed to a continuous bit stream. They are usually broken up into standard groups for readability. Baudot (ITA2), SITOR, and ASCII (ITA 5) are examples of text- based transmission modes. These codes are usually substitutions into lookup tables of longer strings or amounts, though occasionally raw data is transmitted this way, as numbers or encoded into alphanumerics that represent the appropriate binary bits for direct crunching by computers. SYNOP (WMO FM-12) Surface Synoptic Reports SHIP (WMO FM-13) Ship Synoptic Reports Both of the above use a ship callsign or a WMO sea or land station number, followed by a time stamp. Up to four more sections follow, in 5 number groups except for the word ICE + a short text string, if ice observations are being passed in that section of the synopsis. METAR (WMO FM-15) Aviation Routine Observations Hourly reports, usually at airports. SPECI (WMO FM-16) Special Aviation Weather Change For important changes before the next scheduled METAR. Expands to word "SPECIAL" in voice ATIS or VOLMET, both of which use an altered METAR format. DRIFTER (WMO FM-18IX) Drifting Buoy Obs, now BUOY BUOY (WMO FM-18X) Buoy Observations Weather buoys can be treated as ships and pass data in SHIP code, or use this special format labeled SVXX in bulletins. RADOB (WMO FM-20) Radar Observations RADREP (WMO FM-22) Radiological Data PILOT (WMO FM 32) Upper Level Wind PILOT SHIP (WMO FM 33) Upper Level Wind PILOT MOBIL (WMO FM 34) Upper Level Wind TEMP (WMO FM-35) Upper Level Observations TEMP SHIP (WMO FM-36) Upper Level Observations TEMP DROP (WMO FM-37) Aircraft Dropsonde Obs. TEMP MOBIL (WMO FM-38) Upper Level Observations ROCOB (WMO FM-39) Rocketsonde Reports ROCOB SHIP (WMO FM-40) Rocketsonde Reports CODAR (WMO FM-41) Aircraft Report AMDAR (WMO FM-42) Aircraft Report ICEAN (WMO FM-44) Ice report IAC (WMO FM-45) Ship surface observation IAC FLEET (WMO FM-46) Ship surface observation GRID (FM 47-IX Ext) Gridded Data (sent as text) GRID provides observation data and information on how to plot it. The result is a picture. WINTEM (WMO FM-50) Upper-level Winds, Temperatures TAF (WMO FM-51) Terminal Aerodrome Forecasts A series of standard groups for valid times, starting FM "(in voice, "from") for the first, then with BCMG (in voice, "becoming,"). If weather is expected to change before the first valid time, a TEMPO ("temporarily") group is included. TAF, when expanded into plain speech, is part of the VOLMET. ARFOR (WMO FM-53) Aviation Routine Forecasts ROFOR (WMO FM-54) On-Route Aviation Forecasts RADOF (WMO FM-57) Radiological Dose Predictions MAFOR (WMO FM-61) Shipping Area Forecasts TRACKOB (WMO FM-62) Oceanographic Data BATHY (WMO FM-63) Oceanographic Data TESAC (WMO FM-64) Oceanographic Data WAVEOB (WMO FM-65) Oceanographic Data HYDRA (WMO FM-67) Hydrological River Reports HYFOR (WMO FM-68) Hydrological Forecast CLIMAT (WMO FM-71) Surface climatic data CLIMAT SHIP (WMO FM-72) Surface marine climatic data NACLI, CLINP, SPCLI, CLISA, INCLI (WMO FM-73) Oceanic climatic data CLIMAT TEMP (WMO FM-75) Upper-air climatic data CLIMAT TEMP SHIP (WMO FM-76) Upper-air marine climatic data SFAZI (WMO FM-81) Special Atmospheric Reports SFLOC (WMO FM-82) Special Atmospheric Reports SAREP (WMO FM-85) Satellite Cloud Interpretations SATEM (WMO FM-86) Satellite Remote Upper Soundings SARAD (WMO FM-87) Satellite Radiance Observations SATOB (WMO FM-88) Satellite Temps & Radiance Balance CREX (None A.P.) Coded raw data table driven obs. AIRMET Aviation Weather Advisory Like a SIGMET, in a special clipped text format, but for less serious weather features. AIREP ICAO Air Report, like a PIREP PIREP Pilot Report of standard items PIREPs go into a database, to be used by weather offices when briefing pilots. RECCO Aircraft Reconnaissance Report One important use of the RECCO format is for data returned by hurricane aircraft every 30 minutes. TEMPO Rapidly Changing Weather TEMPO is usually part of a TAF, describing weather expected to change within the hour. SIGMET SIGnificant METeorological warning A weather feature that poses a hazard to aviation. In the US, divided into convective (severe thunderstorms or tornadoes), and non- convective (things like turbulence and icing). Interestingly, SIGMET is also an officially defined hypertext markup document type. SIGMETs are in a clipped text format. VORTEX Aircraft Hurricane Observations Data passed from dropsonde aircraft while on the actual pass through the hurricane, including position fix, pressure, wind, and eye structure. Binary Codes ----------- BUFR (WMO FM-94) Binary Universal Form for the Representation of met. data BUFR is a completely binary code for computer crunching, passing data in octets as a binary stream, beginning with the designator BUFR in CCITT ITA5) GRIB (FM 92-IX Ext) Gridded Binary Data GRIB provides observation data and information on how to plot it, but unlike GRIB the data is intended for computer crunching alone. It, too is passed as octets, but in a text form these can show as hexadecimal bytes 00 through FF. The result looks like a "hex dump" with numbers and letters A through F. 7. Weather Code FAQ =================== Here are some common questions seen on Internet, and in mail to Utility World: 1. Q. I found an unid RTTY transmission that looks like "numbers," but the format is weird and some groups have letters. A. Look for things we've talked about, like AAXX, BBXX, METAR, SPECI, TEMPO, or KAWN, and you might be surprised. 2. Q. I went to the Air Force frequencies you wrote about, but nothing happened. A. Since all US HF military weather is on request, the schedules and frequencies are nearly as changeable as, well, the weather. 3. Q. I found the US Air Force FAX you talk about, and I seem to be in sync, but all I get is a skinny white line. A. A lot of these faxes are apparently some sort of raster grid, and if there's no significant weather to plot, all that comes out on the amateur's typical computer screen is the sync beep at the edge. When there is significant weather, it can show up as standard synoptic symbols such as the two lines and a jagged arrow meaning "thunderstorm," or as a number, presumably for a SIGMET or similar. Everything else is black, except for a few groups looking like WMO headers, and maybe a couple of chicken scratchings that are there just because the equipment does these things. This is a good reason not to leave the printer on for Air Force weather fax. 4. Q. I'm getting good copy of the RTTY, but it's all numbers and doesn't fit any of these codes. A. Yes, you've noticed this too. My guess is that it's raw output in some military version of something like GRID, GRIB, or BUFR. 5. Q. So where is the KAWN transmitter anyway? A. It's wherever the US Air Force Automated Weather Network, formerly the Aviation Weather Network, is being picked up and relayed onto the radio. Since KAWN is not a radio callsign, it contains no information as to transmitter locations. The same holds for KGWC, KNHC, etc.. 6. Q. What is QNH? A. Altimeter setting in international and/or Metric units. Below a certain altitude, pilots manually offset their altimeters to compensate for changing barometric pressures which would otherwise cause measurement errors. It comes from an old international procedural "Q" signal from the days of Morse code. Simplified meaning of the old prosign is: QNH? = "What is your station's altimeter setting (usually in Hectopascals) [at -?]," and QNH = "Set your altimeter to - [at - hours]." In the US national practice, "Altimeter" is substituted for "QNH," and the unit is inches of mercury. This is one way to tell whether a voice bulletin is coming from the US or somewhere else. 8. Useful WWW URLs ================== BUFR Code Specifications: http://www-dd.fsl.noaa.gov/bufrFormat.html Details of "Hurricane Hunter" use of RECCO and VORTEX codes: http://www.hurricanehunters.com/ Entry point into weather station designator database: http://www.nws.noaa.gov/oso/oso1/oso12/siteid.htm NCDC Weather Station Locator: http://www.ncdc.noaa.gov/ol/climate/stationlocator.html SHIP synoptic code, with US Navy extensions http://waves.ncdc.noaa.gov/ship/sec1-ch1.htm Terminal Aerodrome Forecast code: http://www.nws.noaa.gov/oso/oso1/oso12/d31/D31links.htm UK Meteorological Office: http://www.met-office.gov.uk/index.html US Federal Meteorological Handbook: http://www.nws.noaa.gov/oso/oso1/oso12/fmh1.htm WMO Technical Library: http://www.wmo.ch/web/arep/lib1/index.html Appendices to this document =========================== 1. Full WMO Heading Decoder 2. Guide to the (BBB) Codes 3. The METAR Code 4. The SYNOP Code 5. The SVXX/BUOY Code Appendix #1: Full WMO Heading Decoder, With Tables ================================================== The FULL symbolic form of the WMO abbreviated heading is: T1T2A1A2ii CCCC YYGGgg (BBB) The full lookup format for the WMO Abbreviated Heading uses a format where the first character of the "Type" field (T1) becomes the key to what the subsequent characters mean, and then some of these can also affect what happens next. This is how a 6- character group can store so much information. The key list of T1 values is Table A from WMO Manual 306, (Code) or Observing / Product Type. It's best visualized as a matrix of jumps to subsequent tables, so that's just what we'll do. Get the first letter T1 from your bulletin, then look across to determine how to interpret subsequent characters, then drop down to the appropriate table and find them. If this whole thing looks like a potentially good use for hypermedia like HTML code, well, it's been done. Try the US web site at http://www.nws.noaa.gov/ TABLE A Data Type Designator T1 Matrix Table for T2A1A2ii definitions T1 Data type T2 A1 A2 ii Priority Max Lgth A Analyses B1 C1 C1 ** 3 3800 B Service message *** *** *** *** 1/2/4* 3800 C Climatic data B1 C1 C1 ** 4 3800 D Grid point information (GRID) B2 C3 C4 D2 3 3800 E Satellite imagery B5 C1 C1 ** 3 (1) F Forecast B1 C1 C1 ** 3 3800 G Grid point information (GRID) B2 C3 C4 D2 3 3800 H Grid point information (GRIB) B2 C3 C4 D2 3 15,000 I Binary observation - BUFR B3 C6 C3 ** 3 15,000 J Binary forecast - BUFR B3 C6 C3 ** 3 15,000 K CREX C7 C7 C3 ** 2 3800 L -- M -- N Notices B1 C1 C1 ** 4 3800 O Oceanographic (GRIB) B4 C3 C4 D1 3 15,000 P Pictorial information(binary) B2 C3 C4 D2 3 15,000 Q Pictorial information regional B2 C3 C5 D2 3 (1) R -- S Surface data B1 C1/C2 C1/C2 ** 2/4* 3800 T Satellite data B1 C3 C4 ** 2 3800 U Upper-air data B1 C1/C2 C1/C2 ** 2 3800 V National data (3) C1 C1 ** (2) (1) W Warnings B1 C1 C1 ** 1 3800 X GRID regional use B2 C3 (2) D2 3 3800 Y GRIB regional use B2 C3 (3) D2 3 15,000 Z GRIB National use (3) (3) (3) (3) 3 15,000 * Priority level: 1 is allocated to service messages 2 is allocated to data and request messages 4 is allocated to seismologic data (T1T2 = SE) or administrative messages ** See Para.2.3.2.2 (of WMO manual) for definition and use *** See Para.2.4.2.3 for definition and use (1) Size to be defined at a later date (2) To be determined later date (3) Table B2 or national table DATA TYPES Y and Z uses National tables in some countries This then selects one of the following: Table B1 - Data Type Designator Table B2 - Data Type Designator Table B3 - Data Type designator Table B4 - Data Type Designator Table B5 - Data Type Designator Table C1 - Geographical Designator Table C2 - Geographical Designator (ships & Ocean) Table C3 - Geographical Designator Table C4 - Reference Time Designator Table C5 - Reference Time Designator Table C6 - Data Type Designator Table C7 - Geographical Designator Table D1 - Level Designator (ocean) Table D2 - Level Designator and U.S. National Tables Table B6 - Data Type Designator Table C8 - Geographical Area Designator (including WMC Washington GRID Numbers) Table C9 - Geographical Area (Tiles) used with KWBx when x = Z Table C10 - Reference Time Designator Table D3 - Level Designator ii T1 is taken from WMO Manual 386 table A. It is an alpha character that designates the general code form of the contents of the bulletin (Coded or plain text). T2 is taken from WMO Manual 386 tables B1 through B6 depending on the designator T1 in table A. It is an alpha character that designates the data type. A1 is taken from WMO Manual 386 tables C1 through C6 depending on designator T1 in table A ( U.S. National practice through C9 ). It is an alpha character that designates the geographical area the content of the bulletin covers. A2 is taken from WMO Manual 386 tables C1 through C5 depending on designator T1 in table A ( U.S. National practice through C9 ). It is an alpha character that designates the geographical area, or may define the forecast period. ii is taken from the WMO Manual 386 paragraph 2.3.2.2 definition, or from table D1 or D2 depending on designator T1 in table A ( U.S. National practice table D3 replaces D2 ). It is a numeric set of two characters. Go to the WMO message structure for more details on this group. When the group ii is used as a US designator, which it is not always the case, it expands to: ii = 40, 50, ... 80 Issued from U.S. Pacific WFO 41, 51, ... 81 Issued from Northeast U.S. WFO or RFC 42, 52, ... 82 Issued from southeast U.S. WFO or RFC (Includes San Juan, PR) 43, 53, ... 83 Issued from North Central U.S. WFO or RFC 44, 54, ... 84 Issued from South Central U.S. WFO or RFC 45, 55, ... 85 Issued from U.S. Rocky Mountains WFO or RFC 46, 56, ... 86 Issued from West Coast WFO or RFC 47, 57, ... 87 Issued from SE Alaska WFO (Juneau, AK) 48, 58, ... 88 Issued from Central Alaska WFO or RFC (Anchorage, AK) 49, 59, ... 89 Issued from NE Alaska WFO (Fairbanks, AK). CCCC is the 4-character international code. YYGGgg is the standard date/time stamp of day, hours, minutes. (BBB) is an optional group of alpha characters, reference BBB Group explanation in the next appendix to this document. Here are the tables for the first group - T1T2A1A2ii: Table A T1: A Analyses B Service message C Climatic data D Grid point information (GRID) E Satellite imagery F Forecast G Grid point information (GRID) H Grid point information (GRIB) I Binary observation - BUFR J Binary forecast - BUFR K CREX L -- M -- N Notices O Oceanographic (GRIB) P Pictorial information(binary) Q Pictorial information regional R -- S Surface data T Satellite data U Upper-air data V National data W Warnings X GRID regional use Y GRIB regional use Z GRIB National use --------------------------------------------------------------- Table B1 T2 (T1 = A, C, F, N, S, T, U or W) T1 = A Analyses C Cyclone [TEXT] G Hydro/Marine [TEXT] H Thickness [TEXT] I Ice FM 44 (ICEAN) O Ozone layer [TEXT] R Radar [TEXT] S Surface FM 45 (IAC)/FM 46 (IAC FLEET) U Upper air FM 45 (IAC) W Weather Summary [TEXT] X Miscellaneous [TEXT] T2 (T1 = C Climatic data): A Climatic anomalies [TEXT] E Monthly means (upper air) FM 76 (CLIMAT TEMP SHIP) H Monthly means (surface) FM 72 (CLIMAT SHIP) Monthly means (ocean areas) FM 73 (NACLI, CLINP, SPCLI, CLISA, INCLI) S Monthly means (surface) FM 71 (CLIMAT) U Monthly means (upper air) FM 75 (CLIMAT TEMP) T2 (T1 = F Forecasts) A Aviation area /GAMET/advisories FM 53 (ARFOR)/[TEXT] B Upper winds and temperatures FM 50 (WINTEM) C Aerodrome (VT › 12 hours) FM 51 (TAF) D Radiological trajectory dose FM 57 (RADOF) E Extended [TEXT] F Shipping FM 46 (IAC FLEET) G Hydrological FM 68 (HYFOR) H Upper air thickness [TEXT] I Iceberg [TEXT] J Radio warning service (incl IUWDS data) [TEXT] K Tropical cyclone advisories [TEXT] L Local/Area [TEXT] M Temperature extremes [TEXT] O Guidance [TEXT] P Public [TEXT] Q Other shipping [TEXT] R Aviation route FM 54 (ROFOR) S Surface FM 45 (IAC)/FM46 (IAC FLEET) T Aerodrome (VT > 12 hours) FM 51 (TAF) U Upper air FM 45 (IAC) V Volcanic ash advisories [TEXT] W Winter sports [TEXT] X Miscellaneous [TEXT] Z Shipping area FM 61 (MAFOR) T2 (T1=N Notices) G Hydrological [TEXT] H Marine [TEXT] N Nuclear emergency response [TEXT] O METNO/WIFMA [TEXT] P Product generation delay [TEXT] T TEST MSG[System related] [TEXT] W Warning related and/or cancellation [TEXT] T2 (T1=S Surface Data) A Aviation routine reports FM 15 (METAR) B Radar reports (part A) FM 20 (RADOB) C Radar reports (part B) FM 20 (RADOB) D Radar reports (parts A & B) FM 20 (RADOB) E Seismic data (SEISMIC) F Atmospherics reports FM 81 (SFAZI)/ FM 82 (SFLOC)/ FM 83 (SFAZU) G Radiological data report FM 22 (RADREP) I Intermediate synoptic hour FM 12 (SYNOP)/ FM 13 (SHIP) L Table driven coded reports FM ?? (CREX) M Main synoptic hour FM 12 (SYNOP)/ FM 13 (SHIP) N Non-standard synoptic hour FM 12 (SYNOP)/ FM 13 (SHIP) O Oceanographic data FM 63 (BATHY)/ FM 64 (TESAC)/ FM 65 (WAVEOB) FM 62 (TRACKOB) P Special aviation weather reports FM 16 (SPECI) R Hydrological (river) reports FM 67 (HYDRA) S Drifting buoy reports FM 18 (DRIFTER) T Sea Ice [TEXT] U Snow depth [TEXT] V Lake ice [TEXT] X Miscellaneous [TEXT] T2 (T1=T Satellite Data) B Satellite orbit parameters [TEXT] C Satellite cloud interpretations FM 85 (SAREP) H Satellite remote upper-air soundings FM 86 (SATEM) R Clear radiance obs FM 87 (SARAD) T Sea surface temperatures FM 88 (SATOB) W Winds & cloud temperatures FM 88 (SATOB) X Miscellaneous [TEXT] Y Radiance Balance TM 88 (SATOB) T2 (T1=U Upper Air Data) A Aircraft reports FM 41(CODAR), ICAO (AIREP) D Aircraft reports FM 42(AMDAR) E Upper-level pressure, FM 35(TEMP)/ FM 36 (TEMP SHIP) temperature, humidity and wind (Part D) FM 38(TEMP MOBIL) F Upper-level pressure, temperature, FM 35(TEMP)/ FM 36 (TEMP SHIP)/ FM 38 (TEMP MOBIL)humidity and wind (Parts C and D) [National and bilateral option] G Upper-wind (Part B) FM 32(PILOT)/ FM 33 (PILOT SHIP)/ FM 34 (PILOT MOBIL) H Upper-wind (Part C) FM 32 (PILOT)/ FM 33 (PILOT SHIP)/ FM 34 (PILOT MOBIL) I Upper-wind (Parts A and B) FM 32 (PILOT)/ FM 33 (PILOT SHIP)/ FM 34 (PILOT MOBIL) [National and bilateral option] K Upper-level pressure, temperature, FM 35(TEMP)/FM 36 (TEMP SHIP)/FM 38 (TEMP MOBIL) humidity and wind (Part B) L Upper-level pressure, temperature, FM 35 (TEMP)/FM 36 (TEMP SHIP)/FM 38 (TEMP MOBIL) humidity and wind (Part C) M Upper-level pressure, temperature, FM 35 (TEMP)/FM 36 (TEMP SHIP)/FM 38 (TEMP MOBIL) humidity and wind (Parts A and B) [National and bilateral option] N Rocketsonde reports FM 39 (ROCOB)/ FM 40 (ROCOB SHIP) P Upper-wind (Part A) FM 32 (PILOT)/ FM 33 (PILOT SHIP)/ FM 34 (PILOT MOBIL) Q Upper-wind (Part D) FM 32 (PILOT)/ FM 33 (PILOT SHIP)/ FM 34 (PILOT MOBIL) R Aircraft report [NATIONAL*] (RECCO) S Upper-level pressure, temperature, FM 35 (TEMP)/FM 36 (TEMP SHIP) humidity and wind (Part A) FM 38 (TEMP MOBIL) T Aircraft report FM 41 (CODAR) X Miscellaneous TEXT] Y Upper-wind (Parts C and D) FM 32 (PILOT)/ FM 33 (PILOT SHIP)/ FM 34 (PILOT MOBIL) [National and bilateral option] Z Upper-level pressure, temperature, FM 37(TEMP DROP), humidity and wind from a sonde released by carrier balloon or aircraft (Parts A, B, C, D) T2 (T1=W Warnings) A Airmet [TEXT] C Tropical cyclone (SIGMET) [TEXT] E Tsunami [TEXT] F Tornado [TEXT] G Hydrological/River Flood [TEXT] H Marine/Coastal Flood [TEXT] O Other [TEXT] S SIGMET [TEXT] T Tropical cyclone (Typhoon/Hurricane) [TEXT] U Severe Thunderstorm [TEXT] V Volcanic Ash Clouds (SIGMET) [TEXT] W Warnings & weather summary [TEXT] ----------------------------------------------------------------- Table B2 T2 (T1 = D, G, H, P, Q, V, X or Y) A Radar data B Cloud C Clear air turbulence D Thickness (relative topography) E Precipitation F Aerological diagrams (Ash cloud) G Significant weather H Height I Ice flow J K Swell height + combinations L Plain language M For national use N Radiation O Vertical velocity P Pressure Q Wet bulb potential temperature R Relative humidity S Snow cover T Temperature U Eastward wind component V X Lifted index Y Observational plotted chart Z Not assigned ------------------------------------------------------------------ Table B3 T2 (T1=I or J Binary Data - BUFR) S Surface/sea level U Upper AirOceanographic/limnographic (water properties) P Pictorial T Text (plain language information) X Other data types Z Mixed data types ------------------------------------------------------------------ Table B4 T2 (T1=O Oceanographic - GRIB) D Depth E Ice concentration F Ice thickness G Ice drift H Ice growth I Ice convergence/divergence Q Temperature anomaly R Depth anomaly S Salinity T Temperature U Current component V not assigned W Temperature warming X Mixed data values ------------------------------------------------------------------ Table B5 T2 (T1 = E Satellite Imagery) C Cloud top temperature F Fog I Infrared Range S Surface temperature V Visible Range W Water vapor Y User specified Z Unspecified ------------------------------------------------------------------ Table C1 Land observation locations A1A2 use the same country codes as seen previously for the identical LL in part 5 of our main document. Please refer to that section. Other Geographical Area Designators: AA Antarctic MP Central Mediterranean AC Arctic MQ Western Mediterranean AE South-East Asia AF Africa NA North America AM Central Africa NT North Atlantic area AO West Africa AP Southern Africa OC Oceana AS Asia OH Sea of Okhotsk AW Near East AX Arabian Sea area PA Pacific area PE Persian area BQ Baltic Sea area PN North Pacific area PQ Western North Pacific CA Caribbean & Central America PS South Pacific area PW Western Pacific area EA East Africa PZ Eastern Pacific area EC East China Sea area EE Eastern Europe SA South America EM Middle Europe SE Southern Ocean area EN Northern Europe SJ Sea of Japan area EU Europe SS South China Sea area EW Western Europe ST South Atlantic area FE Far East XE Eastern hemisphere XN Northern hemisphere GA Gulf of Alaska area XS Southern hemisphere GX Gulf of Mexico area XT Tropical belt XW Western hemisphere IO Indian Ocean area XX For use when others are not appropriate ME Eastern Mediterranean area MM Mediterranean area ---------------------------------------------------------------- Table C2 Geographical Designator A1 A2 1. The first letter A1 will denote the nature of the ship or automatic marine station: For ocean weather stations: W For mobile ships and other marine stations: V 2. The second letter A2 will denote the area from which the reports contained in the bulletin originate: Designator Data Area A Area between 30o N - 60o S, 035o W - 070o E B Area between 90o N - 05o N, 070o E - 180o E C Area between 05o N - 60o S, 120o W - 035o W D Area between 90o N - 05o N, 180o W - 035o W E Area between 05o N - 60o S, 070o E - 120o W F Area between 90o N - 30o N, 035o W - 070o E J Area between 60o S X More than one area ----------------------------------------------------------------- Table C3 Location Codes (A1 when T1=D,G,O,P,or T, A2 when T1= I, J, or K A 0 - 90 W northern hemisphere B 90W - 180 northern hemisphere C 180 - 90E northern hemisphere D 90E - 0 northern hemisphere E 0 - 90W tropical belt F 90W - 180 tropical belt G 180 - 90E tropical belt H 90E - 0 tropical belt I 0 - 90W southern hemisphere J 90W - 180 southern hemisphere K 180 - 90E southern hemisphere L 90E - 0 southern hemisphere N Northern hemisphere P Area between 64.69N - 136.76W, 55.61N - 13.43W 64.69N - 156.76W, 55.61N - 33.43W S Southern hemisphere T 45W - 180 northern hemisphere U Area between 21.0N - 128.1W, 36.0N - 130.9W 21.1N - 113.0W, 36.2N - 110.5W V Area between 30.3N - 83.7W, 51.0N - 68.9W 19.8N - 64.5W, 33.3N - 47.1W X Global Area (area not definable) When T1=H: A 0 - 180 E northern hemisphere [21] B 180 W - 0 northern hemisphere [22] C 0 - 180 E southern hemisphere [23] D 180 W - 0 southern hemisphere [24] E 0 - 355 E northern hemisphere [25] F 0 - 355 E southern hemisphere [26] G Regional use H Not Assigned I 30 W - 60 E northern hemisphere [37] J 60 W - 150 E northern hemisphere [38] K 150 E - 120 W northern hemisphere [39] L 120 W - 30 W northern hemisphere [40] M 30 W - 60 E southern hemisphere [41] N 60 W - 150 E southern hemisphere [42] O 150 E - 120 W southern hemisphere [43] P 120 W - 30 W southern hemisphere [44] Q-S Not Assigned T 0 - 180 E northern hemisphere [61] U 180 W - 0 northern hemisphere [62] V 0 - 180 E southern hemisphere [63] W 180 W - 0 southern hemisphere [64] X Regional use Y-Z Not Assigned ---------------------------------------------------------------- Table C4 Time Designators A2 when T1 = D,G,H,O, P, or T A Analysis (00 hour) B 6 hours forecast C 12 hours forecast D 18 hours forecast E 24 hours forecast F 30 hours forecast G 36 hours forecast H 42 hours forecast I 48 hours forecast J 60 hours forecast K 72 hours forecast L 84 hours forecast M 96 hours forecast N 108 hours forecast O 120 hours forecast P 132 hours forecast Q 144 hours forecast R 156 hours forecast S 168 hours forecast T 10 days forecast U 15 days forecast V 30 days forecast W...Z Not assigned ------------------------------------------------------------------ Table C5 Reference Time Designators (A2 when T1 = Q, X, or Y) A Analysis (00 hour) B 3 hours forecast C 6 hours forecast D 9 hours forecast E 12 hours forecast F 15 hours forecast G 18 hours forecast H 21 hours forecast I 24 hours forecast J 27 hours forecast K 30 hours forecast L 33 hours forecast M 36 hours forecast N 39 hours forecast O 42 hours forecast P 45 hours forecast Q 48 hours forecast R 54 hours forecast [48+6] S 66 hours [+12] T 78 hours U 90 hours V 102 hours W 114 hours X 126 hours Y 138 hours Z 150 hours ------------------------------------------------------------------ Table C6 Data Type Designator (A1 = I, or J) 1. The designators specified in this table should be used to the greatest extent possible to indicate the type of data contained within the body of the BUFR bulletin. 2. Where more than one data type is contained in the bulletin, the designators for only one of the data types should be used. 3. When the table does not contain a suitable designator for the data type, an alphabetic designator which is not assigned in the table should be introduced and the WMO Secretariat notified. T1 = I Observational Data and T2 = S Surface Designator Data type A Land based hourly reports C Climatic reports I Land intermediate synoptic reports M Land based Main synoptic reports N Land based asynoptic intermediate reports P Land based hourly specials S Floating platforms (ship, buoy, etc.) R Hydrologic reports X Other surface data Z Bulletins with mixed data type reports T1 = I Observational Data and T2 = U Upper Air Designator Data type A Single level aircraft reports B Single level balloon reports C Single level satellite derived reports D Dropsonde/dropwindsondes M Model derived sondes N Rocketsondes P Profilers R Radiance data S Radiosondes/pibal reports T Satellite derived sondes X Other upper air reports Z Mixed upper air reports T2 = T TEXT Designator Data type A Administrative message B Service message R Request for data (inclusive of type) X Other text messages of information Z Mixed text types T1 = I Observational Data and T2 = P PICTORIAL Designator Data type I Satellite imagery data R Radar reports X Not defined Z Mixed data types T1 = I or J Observational Data / Forecast Products) and T2 = O Oceanographic/Limnographic Designator Data type I Sea ice S Sea surface and below soundings T Sea surface temperature W Sea surface waves X Other sea environmental Z Mixed collection of oceanographic types T1 = J (Forecast Products) and T2 = S Surface/Sea Level Designator Data type A Surface area forecast (e.g. airway) M Surface forecast (e.g. MOS) P Forecast amendments (e.g. airways) R Hydrologic forecast S Forecast amendments (TAF) T Aerodrome forecast (TAF) X Other surface forecasts Z Mixed collection of forecast types T1 = J (Forecast Products) and T2 = U Upper Air Designator Data type A Forecast at single levels S Forecast soundings X Other upper air forecasts Z Mixed collection of forecast types T1 = J (Forecast Products) and T2 = T TEXT WARNINGS/Notices Designator Data type E Tsunami H Hurricane, typhoon, tropical storm warning S Severe weather, SIGMET T Tornado warning X Other warnings Z Mixed collection of warnings ----------------------------------------------------------------- Table C7 Data Type Designator A1 for Values of T2 = S, U, O, F, and V ( when T1 = K - CREX ) CBS XI, Cairo 1996 1. The designators specified in this table should be used to the greatest extent possible to indicate the CREX type of observational data contained within the body of the bulletin. 2. When the table does not contain a suitable designator for the observational data type, an alphabetic designator which is not assigned in the table should be introduced and the WMO Secretariat notified. 3. In the event no standard format has been established for a particular data type, and there is a recommended format, that format is given in square brackets under the column labeled Code Form (e.g. [ASCII]). This is a character code - International Alphabet No.5 (Attachment II-2) will be used. T2 = S Surface A1 Designator Data type Code Form (CREX) A Land based hourly reports [ASCII] C Climatic reports [ASCII] I Land intermediate synoptic reports [ASCII] M Land based main synoptic reports [ASCII] N Asynoptic intermediate reports [ASCII] P Land based hourly specials [ASCII] S Floating platforms (ship, buoy, etc.) [ASCII] R Hydrologic reports [ASCII] X Other surface reports [ASCII] Z CREX bulletins with mixed data type rpts [ASCII] T2 = U Upper Air A1 Designator Data type Code Form (CREX) A Single Level aircraft reports [ASCII] B Single level balloon reports [ASCII] C Single level satellite derived reports [ASCII] D Dropsondes/dropwindsondes [ASCII] L Ozone data [ASCII] N Rocketsondes [ASCII] P Profiler [ASCII] R Radiance data [ASCII] S Radiosonde/pibal [ASCII] T Satellite derived sondes [ASCII] X Other upper air reports [ASCII] Z Mixed upper air data type reports [ASCII] T2 = O Oceanographic/Liminographic A1 Designator Data type Code Form (CREX) I Sea Ice [ASCII] S Sea surface and below sounding [ASCII] T Sea surface temperature [ASCII] W Sea surface waves [ASCII] X Other sea environmental [ASCII] Z Mixed collection of oceanographic types [ASCII] T2 = F FORECASTS - Surface/Sea Level A1 Designator Data type Code Form (CREX) A Surface area forecast (e.g. airways) [ASCII] M Surface forecasts (e.g. MOS) [ASCII] P Forecast amendments (airways) [ASCII] R Hydrologic forecasts [ASCII] S Forecast amendments (TAF) [ASCII] T Aerodrome forecasts (TAF) [ASCII] X Other surface forecasts [ASCII] Z Mixed collection of forecasts [ASCII] T2 = V FORECASTS - Upper Air A1 Designator Data type Code Form (CREX) A Single level [ASCII] S Soundings [ASCII] X Other upper air forecasts [ASCII] Z Mixed collection of forecasts [ASCII] Note: The allocation of abbreviated headings for CREX messages is pending the formal approval of the code CREX. ----------------------------------------------------------------- Table D1 Level Designators (ii when T1=O) 98 Surface 96 2.5 94 5.0 92 7.5 90 12.5 88 17.5 86 25.0 84 32.5 82 40.0 80 50.0 78 62.5 76 75.0 74 100 72 125 70 150 68 200 66 300 64 400 62 500 60 600 58 700 56 800 54 900 52 1000 50 1100 48 1200 46 1300 44 1400 42 1500 40 1750 38 2000 36 2500 34 3000 32 4000 30 5000 01 Primary layer depth ---------------------------------------------------------------- Table D2 Level Designators (ii when T1= D,G,H,P,Q,X or Y) 99 1000 hPa 98 Air properties for the earth's surface 97 Level of the tropopause 96 Level of maximum wind 95 950 hPa 94 Level of 0oC isotherm 93 Not assigned - 975 hPa(U.S. use) 92 925 hPa 91 Not assigned - 875 hPa(U.S. use) 90 900 hPa 89 Any parameter reduced/sea level (MSLP) 88 Ground/water properties for the earth's surface (i.e. snow cover, wave & swell) 87 1000-500 hPa thickness 86 Boundary Layer 85-01 Hundreds and tens digits of the hectopascal level (e.g. 70 = 700 hPa;03 = 030 hPa) TO INCLUDE: 81 = 810 hPa = 6000ft FL 82 = 825 hPa(U.S. use) 77 = 775 hPa(U.S. use) 73 = 730 hPa = 9000ft FL 72 = 725 hPa(U.S. use) 67 = 675 hPa(U.S. use) 65 = 650 hPa = 12000ft FL 62 = 625 hPa(U.S. use) 00 Entire Atmosphere (e.g. precipitable water) US Tables --------- Table B6 Data Type designator T2 ( when T1 = Y or Z ) U.S. Table for National GRIB Products U.S. National Practice 1. The designator specified in this table should be used to the greatest extent possible to indicate the data types of the data contained within the text of the bulletin. 2. Where the data type does not correspond exactly with the designator, the designator for the most approximate type of the data may be used. 3. The NWS will assign designators to this table in place of the unassigned designators when needed. Designator Data Type A Cloud parameters (ice, water) B Vertical Wind Shear C Vorticity D Probability Values (Thunderstorm, Precip types, Cloud types) E Precipitation parameters (Precip. water, convective Precip.) F Long wave radiation G Temperature Values (Maximum, Minimum, Dew Point) H Height (geopotential) I unassigned J unassigned K Ocean wave properties (Period, Direction) L unassigned M unassigned N unassigned O Vertical velocity/Surface Lifted index P Pressure Q Stability Index R Relative humidity S Snow properties T Temperature U Wind components (U V) V unassigned W Cape/Cin/Helicity X-Z unassigned ------------------------------------------------------------------ Table C8 Geographical area designator A1 (when T1 = H) U.S. National Table derived from WMO Table C3 1. The designator specified in this table should be used to the greatest extent possible to indicate the geographical area of the data contained within the text of the bulletin. 2. Where the geographical area of the data does not correspond exactly with the designator, the designator for the area most approximating that of the data may be used. 3. When the table does not contain a suitable designator for the geographical area, an alphabetic designator which is not assigned in the table will be introduced. Designator Geographical Area A 0 - 180 E northern hemisphere [21] B 180 W - 0 northern hemisphere [22] C 0 - 180 E southern hemisphere [23] D 180 W - 0 southern hemisphere [24] E 0 - 355 E northern hemisphere [25] F 0 - 355 E southern hemisphere [26] G Regional use H Not Assigned I 30 W - 60 E northern hemisphere [37] J 60 W - 150 E northern hemisphere [38] K 150 E - 120 W northern hemisphere [39] L 120 W - 30 W northern hemisphere [40] M 30 W - 60 E southern hemisphere [41] N 60 W - 150 E southern hemisphere [42] O 150 E - 120 W southern hemisphere [43] P 120 W - 30 W southern hemisphere [44] Q-S Not Assigned T 0 - 180 E northern hemisphere [61] U 180 W - 0 northern hemisphere [62] V 0 - 180 E southern hemisphere [63] W 180 W - 0 southern hemisphere [64] X Regional use Y-Z Not Assigned Geographical area designator A1 ( when T1 = Y or Z ) Designator Geographical Area NCEP GRID No. A northern hemisphere [201] B unassigned C unassigned D unassigned E unassigned F unassigned G unassigned H National CONUS w/ Double Resolution [213] I National CONUS [202] J National Alaska [203] K National Hawaii [204] L National Puerto Rico [205] M Regional MARD [206] N Regional Alaska [207] O Regional Hawaii [208] P Regional Puerto Rico [210] Q Regional CONUS [211] R Regional CONUS w/ Double Resolution [212] S Regional MARD w/ Double Resolution [209] T Regional Alaska w/ Double Resolution [214] U Regional CONUS [215] V Regional Alaska [216] W-Z unassigned ------------------------------------------------------------------ Table C9 Geographical-Tile Number designator T2 A1 ( when T1 = Z and the CCCC = KWBZ) ( A DRAFT U.S. National Practice Table ) Instructions for the proper application of the Geographical "TILE" number designator - A two character field of the heading. 1. The designator specified in this table should be used to the greatest extent possible to indicate the geographical high resolution grid tile number of the data contained within the geographical area as specified by the grid squares defined by the producing center of the GRIB bulletin. 2. Where the geographical tile number for the area of the data does not correspond exactly with the designator, the number designator for the area most approximating that area of the data may be used. The exact area of coverage will be available within the GRIB Product Definition Section (PDS) of the bulletin. Designator Geographical Area Tile Number NCEP Model AA - AW 01 - 24 CONUS 20 km tiles meso-Eta AY - AZ unassigned BA - BW 01 - 24 CONUS 20 km tiles RUC BY - BZ unassigned CA - CW unassigned CY - CZ unassigned DA - DZ unassigned EA - EZ unassigned FA - FZ unassigned GA - GZ unassigned HA - KR 01 - 96 CONUS 10 km tiles meso-Eta KS - KZ 01 - 08 Alaska 20 km tiles RUC LA - OR 01 - 96 CONUS 10 km tiles RUC OS - OZ 01 - 08 Hawaii 20 km tiles RUC PA - QZ unassigned RA - RF 01 - 06 CONUS 40 km tiles meso-Eta RG - RL 01 - 06 CONUS 40 km tiles RUC RM - RR 01 - 06 Alaska 40 km tiles meso-Eta RS - RX 01 - 06 Alaska 40 km tiles RUC RY - RZ unassigned SA - SF 01 - 06 Hawaii 40 km tiles meso-Eta SG - SL 01 - 06 Hawaii 40 km tiles RUC SM - ZZ unassigned ----------------------------------------------------------------- Table C10 Reference Time designator A2 (when T1 = Y or Z) 1. The designator specified in this table should be used to the greatest extent possible to indicate the reference time of data contained within the text of the bulletin. 2. When the table does not contain a suitable designator for the reference time, use "Z" and obtain the forecast hour from the GRIB Product Definition Section. Designator Data Type Designator Data Type A Analysis (00 hour) N 18 hours forecast B 1 hour forecast O 24 hours forecast C 2 hours forecast P 30 hours forecast D 3 hours forecast Q 36 hours forecast E 4 hours forecast R 42 hours forecast F 5 hours forecast S 48 hours forecast (2 days) G 6 hours forecast T 60 hours forecast H 7 hours forecast U 72 hours forecast (3 days) I 8 hours forecast V 84 hours forecast J 9 hours forecast W 96 hours forecast (4 days) K 10 hours forecast X 108 hours forecast L 11 hours forecast Y 120 hours forecast (5 days) M 12 hours forecast Z Time contained in PD Block of GRIB code --------------------------------------------------------------------- Table D3 Level designator ii (when T1 = H, X, Y, or Z) (U.S. National Practice definitions included) Instructions for the proper application of level (elevations above the earth's surface) designator. 1. The designator specified in this table should be used to the greatest extent possible to indicate the level of the data contained within the text of the bulletin. 2. When data at more than one level are contained in the text, the designator for only one of the levels should be used. 3. When the table does not contain a suitable designator for the level, a designator which is not assigned in the table should be used. The U.S. Practice uses 25 mb increments 1000-100 mb and are included below. ii Designator Level 00 Entire Atmosphere (e.g. precipitable water) 99 1000 hPa 98 Air properties for the earth's surface 97 Level of the tropopause 96 Level of maximum wind 95 950 hPa 94 Level of 0oC isotherm 93 975 hPa 92 925 hPa 91 875 hPa 90 900 hPa 89 Any parameter reduced/sea level (MSLP) 88 Ground/water properties for the earth's surface (i.e. snow cover, wave & swell) 87 1000-500 hPa thickness 86 Boundary Layer 74 Cloud top level 85-01 Hundreds and tens digits of the hectopascal level(e.g. 70=700 hPa;03=030 hPa) TO INCLUDE: 81 = 810 hPa = 6000ft FL 82 = 825 hPa 84 = 875 hPa 77 = 775 hPa 73 = 730 hPa = 9000ft FL 72 = 725 hPa 67 = 675 hPa 65 = 650 hPa = 12000ft FL 62 = 625 hPa 50 = 510 hPa = 18000ft FL (U.S. National Practice uses 500 mb level) 11 = First 30 mb average thickness [from surface] 12 = Second 30 mb average thickness 13 = Third 30 mb average thickness 14 = Forth 30 mb average thickness 45 = Fifth 30 mb average thickness 16 = Sixth 30 mb average thickness Note: The 810, 730, and 650 hPa levels are not being used as pressure levels, they are being used as geometric heights. Appendix #2: What BBB Codes Mean ================================ GUIDELINES on the USE of the INDICATOR BBB T1T2A1A2ii CCCC YYGGgg (BBB) This line, which is preceded by "format effectors" [ cr ] [ cr ] [ lf ], constitutes the complete WMO abbreviated heading line, which can contain the optional BBB group, indicated by the open and closed parenthesis ( ). General Instructions The WMO abbreviated heading line, including each unique YYGGgg (date time group), shall be used only once a month, due to the day of the month being part of the heading. The indicator BBB shall only be added when a WMO abbreviated heading has already been used for transmission of an initial bulletin. It indicates that the contents to be a delayed, corrected or amended bulletin. The indicator BBB can also be used for segmentation as described below in paragraph 5. The indicator BBB shall only be included in the WMO abbreviated headings of delayed (retard), corrected, or amended bulletins by those centres which are responsible for preparing, or compiling the bulletins concerned, or for communication transmission reasons by any system as a segment sequence indicator when bulletins are segmented to control bulletin size. Once the initial bulletin has been transmitted, the centre responsible for preparing or compiling the original bulletin uses the indicator BBB to transmit delayed or corrected reports or to amend information for the same abbreviated heading containing the same YYGGgg. A centre shall not construct an abbreviated heading with the indicator BBB for delayed, corrected, amended, bulletins having a size larger than the limit defined in TABLE A as it would cause a communications system to segment it before transmission. The Bulletin Segment Heading is a special form of the WMO abbreviated heading where the indicator BBB takes the form of Pxx. The bulletin segment heading replaces the normal WMO abbreviated heading when bulletins are larger than size limit defined in WMO Table A. The bulletin segment heading shall take the place of the WMO abbreviated heading for electronic transmission purposes. The bulletin segment heading is a repeating heading, with a unique Pxx group for each segment. The original WMO bulletin shall be re- constructed from these segments before use. The bulletin segment heading cannot be used in place of a standard WMO abbreviated heading of a bulletin if any of the other indicator BBB options are present. This normally will not be a problem as a delayed, corrected, or amended bulletin with the indicator BBB should be smaller then the initial message. However, the U.S. has established a National practice to support the transmission of plain text bulletins containing an abbreviated heading with a BBB group which are too large for transmission. BBB Forms The four forms of the BBB indicator group are: RRx - Delayed (Retard) CCx - Correction AAx - Amendment Pxx - Segment number Each form precludes the use of the others in the same bulletin. The RRx, CCx, and AAx forms are attributes of the content of the bulletin, and the Pxx is an attribute of the segment number not the content. Each form is described separately below. RRx Indicator Group - Delayed Routine Meteorological Reports [retard] This indicator group has the form RRx; where: x = A through X. It is used to transmit a collection of one or more weather reports which are normally contained in the initial bulletin but which were received after the initial bulletin has been transmitted. The value of x = A is for the first bulletin containing additional reports; a value of x = B for a second bulletin containing additional reports, if necessary, and, so on up to and including x = X. For x = Y it represents a loss of the record of the sequence by the issuing center. For x = Z it represents the compiled bulletin is over 24 hours after the time of observation. CCx Indicator Group -Corrections to Previously Transmitted Reports This indicator group has the form: CCx; where x = A through X. It is used to transmit a bulletin containing corrections to reports that have already been included in a bulletin previously transmitted. The value of x = A is for the first bulletin containing corrected reports; a value of x = B for a second bulletin containing additional corrected reports, if necessary, and, so on up to and including x = X. For x = Y it represents a loss of the record of the sequence by the issuing center. For x = Z it represents the compiled bulletin is over 24 hours after the time of observation. AAx Indicator Group - Amendments to Processed Information This indicator group has the form AAx; where x = A through X. It is used to transmit a bulletin containing amendments to processed information in a bulletin which has previously been sent. The value of x = A is for the first bulletin containing information amending the basic (initial) bulletin; a value of x = B for a second bulletin containing information amending the basic (initial) bulletin, if necessary, and so on up to and including x = X. For x = Y it represents a loss of the record of the sequence by the issuing center. For x = Z it represents the compiled bulletin is over 24 hours after the time of observation. Pxx Indicator Group - Segmentation of a Large Bulletin When a bulletin exceeds the length limit defined in Table A, it shall be segmented for communications purposes using a bulletin segment heading line utilizing the Pxx Indicator Group. There are two different structures possible for segments. Segmented alphanumeric products have a supplementary identification line which repeats information in addition to the bulletin segment heading line in each segment. Segmented binary products do not repeat the supplementary identification line information in a second line for each subsequent segment. Only the bulletin segment heading line is repeated. Defining: Pxx = values of xx = AA through YZ and ZA through ZZ The following principles shall apply when segmenting alphanumeric bulletins for transmission: The first bulletin segment heading will have sequence indicator xx = AA, the second AB and so on up to the last bulletin segment heading which shall have xx = Zx. The Z is a LAST SEGMENT FLAG and is placed in the first x position of the Pxx group of the last segment of the set of bulletin segments with the second x the sequence letter which would have normally been used if this was not the last segment. This special PZx group is required to inform the receiving center that no more bulletin segments exist for this product. And; Any original code form or product identification indicator shall be included in each bulletin segment heading and is called a supplementary identification line. Except for the last segment, segment lengths shall be as long as possible, within approved bulletin length limits [Table A] and formatting constraints. Segmented bulletin breaks shall immediately follow end-of-report indicator signals ( = signs ) when or where available in close proximity to the size limit. When end-of report indicators can't be used, segmented plain text bulletins will be broken on an end- of-line function or on a space if the end-of-line function can not be found in close proximity to the size limit. All WMO Regional Telecommunication Hubs on the Global Telecommunication System should relay bulletin segments as received on the Main Trunk Network. Upon receipt all plain text bulletin segments the receiving end shall re-built the original bulletin prior to use, as the segmentation procedure is for transmission purposes only. Bulletin segments must be processed to re-build the original bulletin to obtain a complete plain text product. U.S. National Practice If it is necessary to segment a bulletin which exceeds the limits established by WMO and the bulletin already utilizes a bulletin attribute (BBB), the following procedures will be used. A bulletin segmentation heading including the appropriate Pxx indicator group will be used; and the original bulletin attribute (BBB) will be included as a separate line followed immediately by the line function carriage return, carriage return, line feed in the first segment only. (see examples below) Binary Bulletins The following principles shall apply when segmenting binary bulletins (i.e. GRIB, BUFR, and T4 FAX bulletins): Bulletin segment lengths shall be as long as possible, as allowed by approved bulletin length limits (except for the last segment) RTHs should relay bulletin segments as received An example of the segmentation of a T4 FAX WMO bulletin that has been received too large according to Table A for onward transmission without segmentation: Example: FIRST BULLETIN SEGMENT PGEE25 KWBC 181200 PAA DFAX 1064 bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbb .....etc... [ until 15000 octets have been reached ] SECOND BULLETIN SEGMENT PGEE25 KWBC 181200 PAB bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbb .....etc... [ until 15000 octets have been reached ] THIRD BULLETIN SEGMENT PGEE25 KWBC 181200 PAC bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbb .....etc... [ until 15000 octets have been reached ] FOURTH and LAST BULLETIN SEGMENT PGEE25 KWBC 181200 PZD bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbb .....etc... [ until something less than 15000 octets have been reached ] Warning ! Bulletin segments must be processed to re-build the original bulletin from it's segment parts to be able to obtain the complete binary bulletin prior to further use. All binary bulletins greater than 15,000 bytes will be segmented unless prior mutual agreement between adjacent centers has established otherwise. The segments will be based upon size only and no consideration will be given to where the break occurs. Bulletin segments will have no additional information added beyond the bulletin segment heading line itself, containing the BBB group of Pxx to accomplish the segmentation process. Additional comments on the use of the BBB groups. An RTH on the GTS should ensure the relay of any bulletins received in accordance with its routing directories even if the bulletins are in fact bulletin segment heading lines and have not been received in the correct sequence. All the bulletin segments containing the indicator Pxx shall be relayed to enable the end user to reconstruct and use the original bulletin. In case of incomplete or incorrect reception, the use of the addressed message for request/reply may be required for recovering incomplete or incorrect bulletin(s). The request for a bulletin segment may be acceptable, or the request for the repeated transmission of the entire set of information (i.e. the whole sequence of bulletin segments) may be necessary, in which case the indicator Pxx would not be used in the request. Appendix #3: The METAR Code =========================== METAR was adopted in 1996 as the world standard, replacing the Airways Code used in the US. More recently, such US broadcasts as ATIS and VOLMET have gone to the METAR form for reporting observations. The biggest change is the use of Celsius for temperature in the US. Exceptions to the international standard allow for the use of feet, inches, and statute miles for other observations. American observations will never have QNH (surface pressure in hectopascals or millibars), while European and other foreign ones usually do, and this is one way to tell them in voice weather traffic such as VOLMET. Although not used in the US, "Ceiling And Visibility OK" (CAVOK) replaces visibility, weather and clouds if: 1) visibility greater than or equal to 10 kilometers; 2) no clouds below 1500 meters or below the highest minimum sector altitude, whichever is greater and no CB; and 3) no precipitation, TS, DS, SS, MIFG, DRDU, DRSA, or DRSN. METAR Format (FM-15) Surface Meteorological Airways Format Syntax: METAR CCCC TIME AUTO WIND VISIBILITY WEATHER CLOUDS TEMP/DEW ALTIMETER REMARKS METAR This defines the product type. METAR regularly reported observation (such as an hourly) SPECI special observation TESTM non-commissioned ASOS report CCCC CCCC is the 4 letter ICAO ID uniquely defining the reporting station. CONUS sites begin with 'K', Alaskan sites begin with 'PA', Hawaiian sites begin with 'PH', Canadian sites begin with 'C', Mexican sites begin with 'MM' TIME The full universal time (UTC) that the observation was taken. The format is: ddhhmmZ. dd is the day of the month, hh is the hour, mm is the minute. Z refers to Zulu time. AUTO This is an optional grouping used in the US to specify a station as being automated. COR This is an optional grouping used in the US to specify an observation as being corrected. WIND The wind group dddssKT or dddssGggKT The value ddd is the wind direction in degrees. The value ss is the wind speed. The units are defined by the string "KT" which is knots. Some reports may have "MPS" for meters per second. If wind gusts are reported, they are specified with the group "Ggg". VISIBILITY The visibility group vvSM or vvKM This specifies the visibility is either statue miles "SM" (US), or kilometers "KM". The visibility can be partial values such as "1 1/2SM" or "3/16SM". Optionally a 4-digit minimum visibility in meters and as required, lowest value with direction. RR/xxxx xxxx Runway Visual Range (optional) R; 2-digit runway designator; Left, Center, or Right as needed; "/"; Minus or Plus (as needed); in U.S, 4-digit value; FeeT in U.S. ; as needed, 4-digit value; Variability; 4-digit value (and tendency Down, Up or No change) WEATHER The weather group iiddppooxx ii is intensity group ii Description - light moderate + heavy VC in the vicinity dd is the descriptor group dd Description MI shallow PR partial BC patches DR low drifting BL blowing SH shower TS thunderstorm FZ freezing pp is the precipitation group pp Description DZ drizzle RA rain SN snow SG snow grains IC ice crystals PE ice pellets GR hail GS small hail/snow pellets UP unknown oo is the obscuration group oo Description BR mist FG fog FU smoke VA volcanic ash DU dust SA sand HZ haze PY spray xx is the misc group xx Description PO dust whirls SQ squalls FC funnel cloud/tornado/waterspout SS duststorm CLOUDS The cloud levels ccchhhtt ccc is the coverage CLR or SKC = clear FEW = 1/8 coverage SCT = 2,3,4/8 coverage BKN = 5,6,7/8 coverage OVC = overcast VV = vertical visibility for obscuration hhh is the height of base in 30m or 100ft increments. ie 30 = 3000 feet tt is an optional type CU = cumulus CB = cumulonimbus TCU = towering cumulus CI = cirrus CAVOK = clear skies, unlimited visibility CAVOK is a widely used national practice, though not in the US. When placed in this group, it means Clouds And Visibility OK. Often NOSIG (No Siginficant features/changes)is placed in the comment field to indicate that this condition will not change for two hours. In automated METAR reports only, CLeaR means "clear below 12,000 feet" TEMP/DEW is the temperature and dewpoint in Celsius TT/DD negative values are preceded with a M (M03 = -3) ALTIMETER is the altimeter setting Qpppp = altimeter in whole mb Apppp = altimeter in .01 in Hg REMARKS The remark section: RMK xxxx xxxx xxxx... Remark Description AO1 AMOS station AO2 ASOS station OBS TAKEN +xx minute offset for observation time SLPppp Sea level pressure in .1 mb (142 = 1014.2 mb) WEA:www Additional present weather information Tttttdddd Current temperature/dewpoint in .1C first digit 1 for negative 1xxxx 6 hour max temp in .1C, first digit 1 for negative 2nnnn 6 hour min temp in .1C, first digit 1 for negative 4/sss Snow coverage in inches 4xxxxnnnn 24 hour max/min temps in .1C, first digit 1 for negative 5tppp Pressure tendency in .1 mb for 3 hours, t is the trend 6pppp 6 hour precipitation in .01 inches 7pppp 24 hour precipitation in .01 inches 8/lmh Cloud type for low, medium, high 933sss New snow coverage, water equivalent 98mmm Equivalent sunshine for day in minutes CITY tt City temperature PCPN pppp Ppppp 1 hour precipitation PK WND sss/nn Peak wind, sss is speed, nn is the time PRESFR Pressure falling rapidly PRESRR Pressure rising rapidly SNOINCR xxx Snow increasing rapidly, where xxx is amount of snow in last hour TSNO Automated station has no thunderstorm detector (US) WSHFT nn Wind shift at time nn Appendix #4: SYNOP Code ======================= SYNOP Data Format (FM-12) Surface Synoptic Observations SYNOP code is the WMO standard method for transmitting surface weather information. It is universal in that separate optional formats exist for different units of measurement. The entire content, except for some plain-text ICE observations, is numeric, and that the format never varies beyond basic standard departures authorized for individual countries. SYNOP is not as easy to read as METAR, but it is easier for a computer to encode and decode. Many programs exist to do just that. Unfortunately, SYNOP codes change frequently, keeping computer programmers on their toes. The official reference for any surface observer in the United States is the Federal Meteorological Handbook No. 1, published jointly by the US Departments of Commerce (NWS), Transportation (FAA), and Defense (AWS/Navy). The complete synoptic code is described in the Federal Meteorological Handbook No. 2 (same publishers as above). The coded report is given in six groups of data, or sections. Sections 0 and 1 are not identified by any special identifying groups, but Sections 2, 3, and 5 are recognizable by the 222, 333, or 555 included as part of the message (Section 4 is not used in the US). Surface marine data (from buoys which report hourly and ships-of-opportunity and weather ships, which report every 6 hours) are found in section 2, which contains reporting formats peculiar to the SHIP code. Several forms of the observation were changed in the late 1990s and are not reflected in most online decoders. These include the 10 m and 20 m wind speed estimates (11 and 22 groups), time and values of maximum winds (3 & 4 groups in section 5), and 10-minute average winds, beginning at the time of observation and working backwards in time (the last 6 groups of section 5 in the CMAN code). 000 Group - Identification and Location 111 Group - Land Observations 222 Group - Sea Surface Observations 333 Group - Climatological Data 444 Group - Clouds below a mountain station, not used in US 555 Group - National Practice Observations Groups 0 and 1 have no beginning designators, but the others, when present will be 222, 333, and 555. Not all groups need occur in all SYNOP. Land stations will obviously not need group 2. Syntax; IIiii or IIIII YYGGi 99LLL QLLLL iihVV Nddff 00fff 1sTTT 2sTTT 3PPPP 4PPPP 5appp 6RRRt 7wwWW 8NCCC 9GGgg 222Dv 0sTTT 1PPHH 2PPHH 3dddd 4PPHH 5PPHH 6IEER 70HHH 8aTTT 333 0.... 1sTTT 2sTTT 3Ejjj 4Esss 5jjjj jjjjj 6RRRt 7RRRR 8Nchh 9SSss 444 Not usually used 555 National practice - varies Section 0: Station & Date/time information ------------------------------------------ IIiii or IIIII YYGGi 99LLL QLLLL For land stations : AAXX YYGGiw IIiii For land stations, the AAXX indicates that the report type follows the WMO SYNOP FM-12 code. Land stations provide the date/time group as do ship stations (see above) through the YYGGiw group. This message usually appears at the start of a bulletin which may contain many reports (see example below). The IIiii group is for the WMO block number (II) and station number (iii) within each block. In the US, the block numbers are: 41 Tropical North Atlantic Ocean (buoys) 42 Gulf of Mexico (buoys) 44 Extratropical N Atlantic Ocean (buoys) 45 Great Lakes (buoys) 46 Tropical NE Pacific Ocean (buoys) 51 Extratropical NE Pacific Ocean (buoys) 70 Alaska 71 Canada 72 Contiguous US (civilian) 74 US (military)* 76 Mexico 78 Central America and Caribbean 80 South America/Caribbean stations 91 Hawaii and US Pacific territories WMO station numbers generally start with 200 and increase to the west along a latitude band, and then at 300 you move up the next latitude band, on the eastern edge of the block number, etc. The southeastern US has station numbers in the low 200's and the Pacific Northwest has station numbers in the high 700's. For ships : BBXX DDDD YYGGiw 99LaLaLa QcLoLoLoLo WMO SYNOP FM-13 is the standard reference for ship SYNOP, which will be designated in the heading by BBXX. It is published in the US by the Navy, and it is also available several places online. SYNOP, like METAR, can also be decoded online. Since buoys are fixed ships, they provide latitude and longitude positions, but also use a WMO station number format (IIiii) rather than the ship ID format DDDD. CMAN (coastal-marine) stations are special types of automated observing stations installed primarily to replace the old lighthouse stations which were staffed by Coast Guard observers. These stations also report in the synoptic code format. IIiii The WMO number of the station. Ship or Buoy Observations: IIIII The ship or buoy identifier YYGGi YY -- The day of the month GG -- The hour of the observation (UTC) iw -- Wind type indicator 0 -- m/s (estimated) 1 -- m/s (from anemometer) 2 -- knots (estimated) 3 -- knots (from anemometer) 99LLL QLLLL LLL -- Latitude of observation to .1 degrees Q -- Quadrant of observation 1 -- North east 3 -- South east 5 -- South west 7 -- North west LLLL -- Longitude of observation to .1 degrees Section 1: International Land Observations ------------------------------------------ iRixhVV Nddff 1snTTT 2snTdTdTd 3PoPoPoPo 4PPPP 5appp 6RRRtR 7wwW1W2 8NhCLCMCH 9GGgg 111 Group - Land Observations iihVV iR -- Precipitation indicator 0 -- Precipitation in groups 1 and 3 1 -- Precipitation reported in group 1 only 2 -- Precipitation reported in group 3 only 3 -- Precipitation omitted, no precipitation 4 -- Precipitation omitted, no observation ix -- Station type and present and past weather indicator 1 -- manned station -- weather group included 2 -- manned station -- omitted, no significant weather 3 -- manned station -- omitted, no weather observation 4 -- automated station -- weather group included (see automated weather codes 4677 and 4561) 5 -- automated station -- omitted, no significant weather 6 -- automated station -- omitted, no weather observation 7 -- automated station -- weather group included (see automated weather codes 4680 and 4531) h -- Cloud base of lowest cloud seen (meters above ground) 0 -- 0 to 50 m 1 -- 50 to 100 m 2 -- 100 to 200 m 3 -- 200 to 300 m 4 -- 300 to 600 m 5 -- 600 to 1000 m 6 -- 1000 to 1500 m 7 -- 1500 to 2000 m 8 -- 2000 to 2500 m 9 -- above 2500 m / -- unknown VV -- Visibility 00 -- less than 0.1 km 01 -- 0.1 km 02 -- 0.2 km ... 50 -- 5.0 km 56 -- 6 km 57 -- 7 km ... 80 -- 30 km 81 -- 35 km 82 -- 40 km 83 -- 45 km 84 -- 50 km 85 -- 55 km 86 -- 60 km 87 -- 65 km 88 -- 70 km 89 -- greater than 70 km 90 -- less than 0.05 km 91 -- 0.05 km 92 -- 0.2 km 93 -- 0.5 km 94 -- 1 km 95 -- 2 km 96 -- 4 km 97 -- 10 km 98 -- 20 km 99 -- greater than 50 km // -- missing Nddff N -- Total cloud cover 0 -- 0 eighths (clear) 1 -- 1/8th 2 -- 2/8ths 3 -- 3/8ths 4 -- 4/8ths 5 -- 5/8ths 6 -- 6/8ths 7 -- 7/8ths 8 -- 8/8ths (overcast) 9 -- sky obscured / -- no observation dd -- wind direction in 10s of degrees ff -- wind speed in units determined by wind type indicator (see above) 00fff (optional) fff -- wind speed if value greater than 100 1sTTT -- Temperature s -- sign of temperature (0=positive, 1=negative) TTT -- Temperature in .1 C 2sTTT -- Dewpoint s -- sign of temperature (0=positive, 1=negative, 9 = RH) TTT -- Dewpoint temperature in .1 C (if sign is 9, TTT is relative humidity) 3PPPP -- Station pressure in 0.1 mb (thousandths digit omitted, last digit can be slash, then pressure in full mb) 4PPPP -- Sea level pressure in 0.1 mb (thousandths digit omitted, last digit can be slash, then pressure in full mb) 4ahhh -- Geopotential of nearest mandatory pressure level (use for high altitude stations where sea level pressure reduction is not accurate) a3 -- mandatory pressure level 1 -- 1000 mb 2 -- 925 mb 5 -- 500 mb 7 -- 700 mb 8 -- 850 mb hhh -- geopotential height omitting thousandths digit 5appp -- Pressure tendency over 3 hours a -- characteristics of pressure tendency 0 -- Increasing, then decreasing -- resultant pressure same or higher 1 -- Increasing, then steady -- resultant pressure higher 2 -- Increasing steadily -- resultant pressure higher 3 -- Decreasing or steady, then increasing -- resultant pressure higher 4 -- Steady -- resultant pressure same 5 -- Decreasing, then increasing -- resultant pressure lower 6 -- Decreasing, then steady -- resultant pressure lower 7 -- Decreasing steadily -- resultant pressure lower 8 -- Increasing or steady, then decreasing -- resultant pressure lower ppp -- 3 hour pressure change in 0.1 mb 6RRRt -- Liquid precipitation RRR -- Precipitation amount in mm 001 -- 1 mm 002 -- 2 mm ... 988 -- 988 mm 989 -- 989 or more mm 990 -- Trace 991 -- 0.1 mm 992 -- 0.2 mm ... 999 -- 0.9 mm t -- Duration over which precipitation amount measured 1 -- 6 hours 2 -- 12 hours 3 -- 18 hours 4 -- 24 hours 5 -- 1 hour 6 -- 2 hours 7 -- 3 hours 8 -- 9 hours 9 -- 15 hours / -- 24 hours 7wwWW -- Present and past weather ww -- Present weather 00 -- clear skies 01 -- clouds dissolving 02 -- state of sky unchanged 03 -- clouds developing Haze, smoke, dust or sand 04 -- visibility reduced by smoke 05 -- haze 06 -- widespread dust in suspension not raised by wind 07 -- dust or sand raised by wind 08 -- well developed dust or sand whirls 09 -- dust or sand storm within sight but not at station Non-precipitation events 10 -- mist 11 -- patches of shallow fog 12 -- continuous shallow fog 13 -- lightning visible, no thunder heard 14 -- precipitation within sight but not hitting ground 15 -- distant precipitation but not falling at station 16 -- nearby precipitation but not falling at station 17 -- thunderstorm but no precipitation falling at station 18 -- squalls within sight but no precipitation falling at station 19 -- funnel clouds within sight Precipitation within past hour but not at observation time 20 -- drizzle 21 -- rain 22 -- snow 23 -- rain and snow 24 -- freezing rain 25 -- rain showers 26 -- snow showers 27 -- hail showers 28 -- fog 29 -- thunderstorms Duststorm, sandstorm, drifting or blowing snow 30 -- slight to moderate duststorm, decreasing in intensity 31 -- slight to moderate duststorm, no change 32 -- slight to moderate duststorm, increasing in intensity 33 -- severe duststorm, decreasing in intensity 34 -- severe duststorm, no change 35 -- severe duststorm, increasing in intensity 36 -- slight to moderate drifting snow, below eye level 37 -- heavy drifting snow, below eye level 38 -- slight to moderate drifting snow, above eye level 39 -- heavy drifting snow, above eye level Fog or ice fog 40 -- Fog at a distance 41 -- patches of fog 42 -- fog, sky visible, thinning 43 -- fog, sky not visible, thinning 44 -- fog, sky visible, no change 45 -- fog, sky not visible, no change 46 -- fog, sky visible, becoming thicker 47 -- fog, sky not visible, becoming thicker 48 -- fog, depositing rime, sky visible 49 -- fog, depositing rime, sky not visible Drizzle 50 -- intermittent light drizzle 51 -- continuous light drizzle 52 -- intermittent moderate drizzle 53 -- continuous moderate drizzle 54 -- intermittent heavy drizzle 55 -- continuous heavy drizzle 56 -- light freezing drizzle 57 -- moderate to heavy freezing drizzle 58 -- light drizzle and rain 59 -- moderate to heavy drizzle and rain Rain 60 -- intermittent light rain 61 -- continuous light rain 62 -- intermittent moderate rain 63 -- continuous moderate rain 64 -- intermittent heavy rain 65 -- continuous heavy rain 66 -- light freezing rain 67 -- moderate to heavy freezing rain 68 -- light rain and snow 69 -- moderate to heavy rain and snow Snow 70 -- intermittent light snow 71 -- continuous light snow 72 -- intermittent moderate snow 73 -- continuous moderate snow 74 -- intermittent heavy snow 75 -- continuous heavy snow 76 -- diamond dust 77 -- snow grains 78 -- snow crystals 79 -- ice pellets Showers 80 -- light rain showers 81 -- moderate to heavy rain showers 82 -- violent rain showers 83 -- light rain and snow showers 84 -- moderate to heavy rain and snow showers 85 -- light snow showers 86 -- moderate to heavy snow showers 87 -- light snow/ice pellet showers 88 -- moderate to heavy snow/ice pellet showers 89 -- light hail showers 90 -- moderate to heavy hail showers Thunderstorms 91 -- thunderstorm in past hour, currently only light rain 92 -- thunderstorm in past hour, currently only moderate to heavy rain 93 -- thunderstorm in past hour, currently only light snow or rain/snow mix 94 -- thunderstorm in past hour, currently only moderate to heavy snow or rain/snow mix 95 -- light to moderate thunderstorm 96 -- light to moderate thunderstorm with hail 97 -- heavy thunderstorm 98 -- heavy thunderstorm with duststorm 99 -- heavy thunderstorm with hail W1 -- Past weather (type 1) W2 -- Past weather (type 2) 0 -- cloud covering less than half of sky 1 -- cloud covering more than half of sky during part of period and more than half during part of period 2 -- cloud covering more than half of sky 3 -- sandstorm, duststorm or blowing snow 4 -- fog, or thick haze 5 -- drizzle 6 -- rain 7 -- snow or mixed rain and snow 8 -- showers 9 -- thunderstorms 8NCCC -- Cloud type information N -- Amount of low clouds covering sky, if no low clouds, the amount of the middle clouds CL -- Low cloud type 0 -- no low clouds 1 -- cumulus humulis or fractus (no vertical development) 2 -- cumulus mediocris or congestus (moderate vertical development) 3 -- cumulonimbus calvus (no outlines nor anvil) 4 -- stratocumulus cumulogenitus (formed by spreading of cumulus) 5 -- stratocumulus 6 -- stratus nebulosus (continuous sheet) 7 -- stratus or cumulus fractus (bad weather) 8 -- cumulus and stratocumulus (multilevel) 9 -- cumulonimbus with anvil / -- low clouds unobserved due to darkness or obscuration CM -- Middle cloud type 0 -- no middle clouds 1 -- altostratus translucidous (mostly transparent) 2 -- altostratus opacus or nimbostratus 3 -- altocumulus translucidous (mostly transparent) 4 -- patches of altocumulus (irregular, lenticular) 5 -- bands of altocumulus 6 -- altocumulus cumulogenitus (formed by spreading of cumulus) 7 -- altocumulus (multilayers) 8 -- altocumulus castellanus (having cumuliform tufts) 9 -- altocumulus of a chaotic sky / -- middle clouds unobserved due to darkness or obscuration CH -- High cloud type 0 -- no high clouds 1 -- cirrus fibratus (wispy) 2 -- cirrus spissatus (dense in patches) 3 -- cirrus spissatus cumulogenitus (formed out of anvil) 4 -- cirrus unicus or fibratus (progressively invading sky) 5 -- bands of cirrus or cirrostratus invading sky (less than 45 degree above horizon) 6 -- bands of cirrus or cirrostratus invading sky (more than 45 degree above horizon) 7 -- cirrostratus covering whole sky 8 -- cirrostratus not covering sky but not invading 9 -- cirrocumulus / -- high clouds unobserved due to darkness or obscuration 9GGgg -- Time of observation in hours and minutes Section 2: International Sea Surface Observations ------------------------------------------------- 222Dv 0sTTT 1PPHH 2PPHH 3dddd 4PPHH 5PPHH 6IEER 70HHH 8aTTT 222Dv D -- direction of ship movement 0 -- calm 1 -- NE 2 -- E 3 -- SE 4 -- S 5 -- SW 6 -- W 7 -- NW 8 -- N 9 -- unknown v -- ship's average speed 0 -- 0 knots 1 -- 1 to 5 knots 2 -- 6 to 10 knots 3 -- 11 to 15 knots 4 -- 16 to 20 knots 5 -- 21 to 25 knots 6 -- 26 to 30 knots 7 -- 31 to 35 knots 8 -- 36 to 40 knots 9 -- over 40 knots 0sTTT -- Sea surface temperature s -- sign of temperature (0=positive, 1=negative) TTT -- Temperature in .1 C 1PPHH -- Wave heights in 0.5 m increments PP -- Period of waves in seconds HH -- Height of waves in 0.5 m increments 2PPHH -- Wave period and heights (instrumented) 3dddd -- Direction of swells (up to 2 swells) 4PPHH -- Period and direction of first set of swells 5PPHH -- Period and direction of second set of swells 6IEER -- Ice accretion on ships 70HHH -- Wave heights to 0.1 m (instrumented) 8aTTT -- Wet bulb temperature Section 3: Special Regional or Climatological Data -------------------------------------------------- 333 0.... 1sTTT 2sTTT 3Ejjj 4Esss 5jjjj jjjjj 6RRRt 7RRRR 8Nchh 9SSss 333 0.... -- Regionally developed data 1sTTT -- Maximum temperature over previous 24 hours s -- sign of temperature (0=positive, 1=negative) TTT -- Temperature in .1 C 2sTTT -- Minimum temperature over previous 24 hours s -- sign of temperature (0=positive, 1=negative) TTT -- Temperature in .1 C 3Ejjj -- Regionally developed data 4Esss -- Snow depth E -- State of ground with snow cover 0 -- predominantly covered with ice 1 -- compact or wet snow covering less than half of ground 2 -- compact or wet snow covering more than half of ground but not completely covered 3 -- even layer of compact or wet snow covering entire ground 4 -- uneven layer of compact or wet snow covering entire ground 5 -- loose dry snow covering less than half of ground 6 -- loose dry snow covering more than half of ground but not completely covered 7 -- even layer of loose dry snow covering entire ground 8 -- uneven layer of loose dry snow covering entire ground 9 -- snow covering ground completely with deep drifts sss -- snow depth in cm 5jjjj jjjjj -- Additional information (can be multiple groups) 6RRRt -- Liquid precipitation RRR -- Precipitation amount in mm 001 -- 1 mm 002 -- 2 mm ... 988 -- 988 mm 989 -- 989 or more mm 990 -- Trace 991 -- 0.1 mm 992 -- 0.2 mm ... 999 -- 0.9 mm t -- Duration over which precipitation amount measured 1 -- 6 hours 2 -- 12 hours 3 -- 18 hours 4 -- 24 hours 5 -- 1 hour 6 -- 2 hours 7 -- 3 hours 8 -- 9 hours 9 -- 15 hours / -- 24 hours 7RRRR -- 24 hour precipitation in mm 8NChh -- Cloud layer data N -- cloud coverage of layer C -- genus of cloud 0 -- cirrus (Ci) 1 -- cirrocumulus (Cc) 2 -- cirrostratus (Cs) 3 -- altocumulus (Ac) 4 -- altostratus (As) 5 -- nimbostratus (Ns) 6 -- stratocumulus (Sc) 7 -- stratus (St) 8 -- cumulus (Cu) 9 -- cumulonimbus (Cb) / -- cloud not visible hh -- height of cloud base 00 -- less than 30 m 01 -- 30 m (100 ft) 02 -- 60 m (200 ft) 03 -- 90 m (300 ft) ... 50 -- 1500 m (5000 ft) 56 -- 1800 m (6000 ft) 57 -- 2100 m (7000 ft) ... 80 -- 9000 m (30000 ft) 81 -- 10500 m 82 -- 12000 m ... 88 -- 21000 m 89 -- greater than 21000 m 90 -- 0 to 50 m 91 -- 50 to 100 m 92 -- 100 to 200 m 93 -- 200 to 300 m 94 -- 300 to 600 m 95 -- 600 to 1000 m 96 -- 1000 to 1500 m 97 -- 1500 to 2000 m 98 -- 2000 to 2500 m 99 -- above 2500 m 9SSss -- Supplementary information 333 identifier for section 3 1snTxTxTx 6-hr maximum temperature 2snTnTnTn 6-hr minimum temperature 4E'sss E' is the state of the ground (normally / in the US) and sss is the depth of snow on the ground, in cm. 7R24R24R24R24 24-hr precipitation amount, in 0.1 mm increments 8NsChshs This group is for the encoding of multiple cloud layers in terms of the ten basic cloud groups; each cloud group (identified by the C) may cover up to Ns oktas of the sky and may have a base encoded in hshs. 9SPSPspsp These are for special phenomena. Section 4: Not used ---------------------------------------------------- Section 5: Meteorological data for national exchange ---------------------------------------------------- Begins with 555 if present In the US: 555 [RECORD] [0itDtDtDt] [1snTT snTxTxsnTnTn] [RECORD] [2R24R24R24R24] [marine/CMAN stations] 11fff10 22fff20 3GGggvx 4dddffvx 6GGgg dddfff0 dddfff1 dddfff2 dddfff3 dddfff4 dddfff5 [US land stations] 9YYGG is repeated [] = optional Appendix #5: BUOY Code ====================== The header SSVX identifies bulletins of observations coded in FM 18-X. Note: This code form replaced the former FM 18-IX Ext DRIFTER code. Observations from buoys similar to observations from ships are encoded in the SHIP code, FM 12 or FM 13, and are included in bulletins headed SMV/, SIV/ etc. For a full decode please refer to the WMO Manual on Codes, Volume I.1 Part A: Alphanumeric codes, WMO Publication No 306, available from: The WMO Secretariat at PO Box 2300, CH-1211 Geneva 2, Switzerland, price Sw Fr 130.- (February 1998) The following Sections are only included if there are data available SECTION 0 Identification, time and position data MiMiMjMj A1bwnbnbnb YYMMJ GGggiw QcLaLaLaLaLa LoLoLoLoLoLo (6QiQt//) SECTION 1 Meteorological and other non-marine data (111QdQx 0ddff 1snTTT 2snTdTdTd OR 29UUU 3P0P0P0P0 4PPPP 5appp SECTION 2 Surface marine data (222QdQx 0snTwTwTw 1PwaPwaHwaHwa ..... ..... SECTION 3 Temperatures, salinity and current (when available) at selected depths 333Qd1Qd2 ..... ..... SECTION 4 Information on engineering and technical parameters including quality control data) 444 (1QpQ2QTwQ4) ..... ..... INTERPRETATION SECTION 0 (Identification, time and position data) MiMiMjMj Always coded as ZZYY A1bwnbnbnb The buoy number or identifier A1bw The WMO Region and sub-region in which the buoy was deployed, eg 62 includes the seas around the UK and to the west and south-west of the British Isles. nbnbnb Type and serial number of the buoy (500 is added to the serial number when the buoy is a drifting buoy) YYMMJ YY Date MM Month J Last digit of the year GGggiw GGgg Time of the observation iw Indicator for source and units of wind speed 0 or 1: Wind speed metres/sec; 3 or 4: Wind speed knots QcLaLaLaLaLa Qc Quadrant of the globe N hemisphere: 7 is degrees West, 1 is degrees East S hemisphere: 5 is degrees West, 3 is degrees East LaLaLaLaLa Latitude (eg 54126 decoded as 54.126 degrees, 54.12/ decoded as 54.12 degrees and 541// as 54.1 degrees) LoLoLoLoLoLo Longitude (eg 132463 decoded as 132.463 degrees, 05621/decoded as 56.21 degrees, and 1458// as 145.8 degrees (6QiQt//) Quality control indicators (see WMO Manual on Codes) SECTION 1 (Meteorological and other non-marine data) 111QdQx Quality control indicators for the section 0ddff 0 Indicator dd Wind direction in tens of degrees ff Wind speed in knots or m/s 1snTTT 1 Indicator sn Sign of temperature - 0: positive or zero, 1: negative TTT Dry-bulb temperature in tenths of a degree Celsius 2snTdTdTd 2 Indicator sn Sign of temperature TdTdTd Dew-point temperature in tenths of a degree Celsius OR 29UUU 2 Indicator 9 Relative humidity follows UUU Relative humidity expressed as a percentage: first figure zero except when UUU is 100 percent 3P0P0P0P0 3 Indicator P0P0P0P0 Pressure at station level, in tenths of a millibar, omitting the thousands digit 4PPPP 4 Indicator PPPP Mean sea level pressure, in tenths of a millibar, omitting the thousands digit 5appp 5 Indicator a Characteristic of pressure change ppp Pressure change over last three hours in tenths of a millibar