NOUS41 KWBC 261941 PNSWSH TECHNICAL IMPLEMENTATION NOTICE 08-74 NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC 340 PM EDT FRI SEP 26 2008 TO: NATIONAL WEATHER SERVICE /NWS/ OFFICES FEDERAL AVIATION ADMINISTRATION USERS FAMILY OF SERVICES SUBSCRIBERS OTHER USERS OF NWS AVIATION FORECASTS FROM: KEVIN L. JOHNSTON CHIEF AVIATION SERVICES BRANCH NWS OFFICE OF CLIMATE WATER AND WEATHER SERVICES SUBJECT: AVIATION WEATHER CENTER /AWC/ GRAPHICAL AIRMET /G-AIRMET/ WILL BE EXPERIMENTAL EFFECTIVE OCTOBER 1 2008 NOTE: THE FOLLOWING HAS NO IMPACT ON NOAA WEATHER WIRE SUBSCRIBERS REFERENCE: TECHNICAL IMPROVEMENT NOTICE /TIN/ 08-40. AS OF OCTOBER 1 2008 THE GRAPHICAL AIRMANS METEOROLOGICAL ADVISORY /G-AIRMET/ WILL BE CLASSIFIED EXPERIMENTAL UNTIL THE FEDERAL AVIATION ADMINISTRATION /FAA/ COMPLETES A REQUIRED OPERATIONAL SUITABILITY EVALUATION AND A SAFETY RISK ASSESSMENT. THE TEXT AIRMET BULLETIN REMAINS OPERATIONAL AND AVAILABLE FOR FLIGHT PLANNING OR BRIEFING PURPOSES. TABLE 1 SHOWS THE AIRMET BULLETINS AVAILABLE FOR CONUS. THE EXPERIMENTAL G-AIRMET IS A TIME SERIES DEPICTION OF AVIATION WEATHER HAZARDS AND ELEMENTS OCCURRING WITH OCCASIONAL OR GREATER FREQUENCY THROUGHOUT THE CONTERMINOUS U.S. AND ADJACENT COASTAL WATERS IN BUFR-FORMAT. THE AVIATION WEATHER HAZARDS AND ELEMENTS DEPICTED ARE: 1. SURFACE VISIBILITY /IFR VIS/ BELOW THREE /3/ STATUTE MILES... INCLUDING THE WEATHER CAUSING THE VISIBILITY RESTRICTION. 2. CLOUD CEILINGS /IFR CIG/ WITH BASES LESS THAN 1000 FEET ABOVE GROUND LEVEL /AGL/. 3. WIDESPREAD MOUNTAIN OBSCURATION /MTN OBSCN/ WHERE VISUAL METEOROLOGICAL CONDITIONS /VMC/ CANNOT BE MAINTAINED... INCLUDING THE WEATHER CAUSING THE OBSCURATION. 4. MODERATE TURBULENCE /MOD TURB/...INCLUDING THE TOP AND BOTTOM ALTITUDES OF THE TURBULENCE LAYER. 5. SUSTAINED SURFACE WIND GREATER THAN 30 KNOTS /STG SFC WND/. 6. NON-CONVECTIVE LOW LEVEL WIND SHEAR POTENTIAL BELOW 2000 FEET AGL /LLWS/. 7. MODERATE ICING /MOD ICE/...INCLUDING THE TOP AND BOTTOM ALTITUDES OF THE ICING LAYER. WHEN THE BOTTOM ALTITUDE IS GIVEN AS FREEZING LEVEL /FRZLVL/ THE RANGE OF FREEZING LEVEL ALTITUDES IS ALSO PROVIDED. 8. FREEZING LEVEL /FRZLVL/ CONTOURS AT THE SURFACE AND AT 4000...8000...12000...AND 16000 FEET ABOVE MEAN SEA LEVEL. 9. MULTIPLE FREEZING LEVELS /M_FZLVL/...INCLUDING THE HEIGHT OF THE HIGHEST AND LOWEST FREEZING LEVELS. THE EXPERIMENTAL G-AIRMET WILL BE ISSUED ROUTINELY AT 0255... 0855...1455...AND 2055 UTC AND AMENDED AS NECESSARY BETWEEN ROUTINE ISSUANCES. EACH ROUTINE ISSUANCE IS VALID THROUGH 12 HOURS WITH A TIME RESOLUTION OF NO MORE THAN THREE /3/ HOURS. THERE ARE THREE /3/ BUFR MESSAGES IN THE G-AIRMET: -ONE FOR ITEMS 1 THROUGH 3 /SIERRA/ -ONE FOR ITEMS 4 THROUGH 6 /TANGO/ -ONE FOR ITEMS 7 THROUGH 9 /ZULU/. A DETAILED DESCRIPTION OF THE EXPERIMENTAL GRAPHICAL AIRMET AND THE BUFR ENCODE/DECODE SCHEME IS AVAILABLE AT /USE LOWER CASE/: HTTP://AVIATIONWEATHER.GOV/NOTICE/G-AIRMET REAL-TIME EXAMPLES OF THE EXPERIMENTAL GRAPHICAL AIRMET ARE AVAILABLE AT /USE LOWER CASE/: HTTP://AVIATIONWEATHER.GOV/TESTBED/GFA TABLE1: AIRMET BULLETINS FOR CONUS WMO HEADER AWIPS ID DESCRIPTION PORTION OF CONUS ---------------------------------------------------------- WAUS41 KKCI MKCWA1S AIRMET SIERRA NORTHEASTERN WAUS41 KKCI MKCWA1T AIRMET TANGO NORTHEASTERN WAUS41 KKCI MKCWA1Z AIRMET ZULU NORTHEASTERN ---------------------------------------------------------- WAUS42 KKCI MKCWA2S AIRMET SIERRA SOUTHEASTERN WAUS42 KKCI MKCWA2T AIRMET TANGO SOUTHEASTERN WAUS42 KKCI MKCWA2Z AIRMET ZULU SOUTHEASTERN ---------------------------------------------------------- WAUS43 KKCI MKCWA3S AIRMET SIERRA NORTH CENTRAL WAUS43 KKCI MKCWA3T AIRMET TANGO NORTH CENTRAL WAUS43 KKCI MKCWA3Z AIRMET ZULU NORTH CENTRAL ---------------------------------------------------------- WAUS44 KKCI MKCWA4S AIRMET SIERRA SOUTH CENTRAL WAUS44 KKCI MKCWA4T AIRMET TANGO SOUTH CENTRAL WAUS44 KKCI MKCWA4Z AIRMET ZULU SOUTH CENTRAL ---------------------------------------------------------- WAUS45 KKCI MKCWA5S AIRMET SIERRA ROCKY MOUNTAIN WAUS45 KKCI MKCWA5T AIRMET TANGO ROCKY MOUNTAIN WAUS45 KKCI MKCWA5Z AIRMET ZULU ROCKY MOUNTAIN ---------------------------------------------------------- WAUS46 KKCI MKCWA6S AIRMET SIERRA PACIFIC COAST WAUS46 KKCI MKCWA6T AIRMET TANGO PACIFIC COAST WAUS46 KKCI MKCWA6Z AIRMET ZULU PACIFIC COAST FOR ADDITIONAL INFORMATION CONTACT: CLINTON E. WALLACE CHIEF AVIATION BRANCH AVIATION WEATHER CENTER KANSAS CITY MISSOURI PHONE: 816-584-7248 E-MAIL: CLINTON.WALLACE@NOAA.GOV NWS TECHNICAL IMPLEMENTATION NOTICES ARE ONLINE AT /USE LOWER CASE/: HTTP://WWW.WEATHER.GOV/OS/NOTIF.HTM $$ NNNN