NOUS41 KWBC 041102 AAA PNSWSH Technical Implementation Notice 12-25 Amended National Weather Service Headquarters Washington DC 702 AM EDT Mon Jun 4 2012 To: Subscribers: -Family of Services -NOAA Weather Wire Service -Emergency Managers Weather Information Network -NOAAPORT Other NWS Partners, Users and Employees From: Tim McClung Science Plans Branch Chief Office of Science and Technology Subject: Amended: Update to GFS-based Model Output Statistics (MOS) Wind Guidance and resulting changes to LAMP wind guidance: Implementation postponed to June 12, 2012 Amended to postpone implementation to June 12, 2012 On Tuesday, June 12, 2012, beginning with the 1200 Coordinated Universal Time (UTC) model cycle, the NWS Meteorological Development Laboratory will implement new Global Forecast System (GFS)-based Model Output Statistics (MOS) wind speed and direction guidance for sites available in the short-range (MAV) and extended-range (MEX) text bulletins. These new equations correct bias changes in the GFS model upgrade implemented May 10, 2011: www.nws.noaa.gov/os/notification/tin11-07gfs_update_aaa.htm These changes also will impact the GFS-based Localized Aviation MOS Program (LAMP) beginning with the 1600 UTC Run. Geographic expanses of certain vegetation types in the southern and western United States correspond to areas where degradation in the MOS wind guidance was most evident, particularly in the warm season. Wind equations are being replaced for most stations over the CONUS. The GFS model upgrade has shown little impact on MOS guidance over ocean water so the current set of equations for all marine stations will remain in place. Guidance for stations in Alaska and neighboring Canadian sites also are not being replaced at this time because verification of the new equations shows a slight degradation in skill. Three METAR sites in the West no longer report or do not contain a sufficient number of wind observations from which to develop new equations. Forecasts produced from the old equations are significantly degraded. Guidance for wind direction and speed will be missing for the following three sites for all cycles and projections in the MAV and MEX bulletins: K4BM Wilkerson Pass, CO KBJN Tonopah Range 74 Nellis AFB, NV KTDO Toledo-Winlock Memorial, WA As a result of the GFS MOS change above, LAMP guidance for wind direction, speed, and gusts will now be missing for the following site for all cycles and projections in the LAMP LAV bulletins and BUFR messages: KTDO Toledo-Winlock Memorial, WA In addition, guidance for wind direction and speed has been added for the following two Air Force sites for all cycles and projections in the Air Force MAV and MEX bulletins: KBYS Bicycle Lake Army Airfield, CA KL35 Big Bear City Airport, CA These changes will slightly alter the format of the MAV and MEX text products because lines for wind direction and speed will be added or removed for the 5 sites listed above. These changes will slightly alter the format of the LAV text products because lines for wind direction, speed, and gusts will be removed for the 1 site listed above. The tables below list the communication identifiers for all products affected by these changes. A temporary Website has been made available until the new equations are implemented so users may compare the current operational GFS MOS wind speed with the improved GFS MOS wind speed guidance. The comparison page can be found at: http://www.mdl.nws.noaa.gov/~mos/mos/gfsmos_wind/ Table 1: Communication identifiers for the GFS-based MOS public text products affected by the changes. WMO HEADING AWIPS ID WMO HEADING AWIPS ID (SHORT RANGE) (EXTENDED RANGE) -------------------- ---------------------- FOPA20 KWNO MAVPA0 FEPA20 KWNO MEXPA0 FOUS21 KWNO MAVNE1 FEUS21 KWNO MEXNE1 FOUS22 KWNO MAVSE1 FEUS22 KWNO MEXSE1 FOUS23 KWNO MAVNC1 FEUS23 KWNO MEXNC1 FOUS24 KWNO MAVSC1 FEUS24 KWNO MEXSC1 FOUS25 KWNO MAVRM1 FEUS25 KWNO MEXRM1 FOUS26 KWNO MAVWC0 FEUS26 KWNO MEXWC0 Table 2: Communication identifiers for the affected Air Force MOS text products. WMO HEADING AWIPS ID WMO HEADING AWIPS ID (SHORT RANGE) (EXTENDED RANGE) --------------------- ---------------------- FOUS30 KWNO MAVF26 FEUS30 KWNO MEXF26 Table 3. Communication identifiers for the GFS-based MOS BUFR products affected by the changes. WMO HEADING WMO HEADING REGION (SHORT RANGE) (EXTENDED RANGE) ------------ ----------- ------------------ JSML30 KWNO JSMT30 KWNO PACIFIC REGION JSML31 KWNO JSMT31 KWNO NORTHEAST CONUS JSML32 KWNO JSMT32 KWNO SOUTHEAST CONUS JSML33 KWNO JSMT33 KWNO NORTH CENTRAL CONUS JSML34 KWNO JSMT34 KWNO SOUTH CENTRAL CONUS JSML35 KWNO JSMT35 KWNO ROCKY MOUNTAIN CONUS JSML36 KWNO JSMT36 KWNO WEST COAST CONUS Table 4: Communication identifiers for the GFS-based LAMP public text product affected by the changes. WMO HEADING AWIPS ID ----------- -------- FOUS11 KWNO LAVUSA Table 5: Communication identifiers for the GFS-based LAMP BUFR products affected by the changes. WMO HEADING REGION ------------ --------------- JSMF10 KWNO PACIFIC REGION JSMF11 KWNO NORTHEAST CONUS JSMF12 KWNO SOUTHEAST CONUS JSMF13 KWNO NORTH CENTRAL CONUS JSMF14 KWNO SOUTH CENTRAL CONUS JSMF15 KWNO ROCKY MOUNTAIN CONUS JSMF16 KWNO WEST COAST CONUS For questions regarding the update to the GFS MOS wind guidance and resulting changes to the MAV and MEX bulletins contact: Kathryn Gilbert MDL/Silver Spring, Maryland 301-713-0023, Ext. 130 Kathryn.Gilbert@noaa.gov For questions regarding the changes to LAMP guidance contact: Judy Ghirardelli MDL/Silver Spring, Maryland 301-713-0056, Ext. 194 Judy.Ghirardelli@noaa.gov Links to the MOS products and descriptions are online at: http://www.nws.noaa.gov/mdl/synop NWS national Technical Implementation Notices are online at: http://www.weather.gov/os/notif.htm $$