TECHNICAL IMPLEMENTATION NOTICE 08
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
315 PM EST WED SEPT 18 2008
TO: FAMILY OF SERVICES /FOS/ SUBSCRIBERS...NOAA
WEATHER WIRE SERVICE /NWWS/SUBSCRIBERS...EMERGENCY
MANAGERS WEATHER INFORMATION NETWORK /EMWIN/
SUBSCRIBERS... NOAAPORT SUBSCRIBERS...OTHER
NATIONAL WEATHER SERVICE /NWS/ CUSTOMERS AND
PARTNERS...NWS EMPLOYEES
FROM: JASON TUELL
SCIENCE PLANS BRANCH CHIEF
OFFICE OF SCIENCE AND TECHNOLOGY
SUBJECT: GLOBAL FORECAST SYSTEM CHANGES:
EFFECTIVE DECEMBER 9, 2008.
EFFECTIVE DECEMBER 9, 2008...BEGINNING WITH THE 1200 COORDINATED
UNIVERSAL TIME /UTC/ RUN...the formulation of the freezing level will be CHANGED, SEVERAL new PARAMETERS WILL BE added TO THE GLOBAL FORECAST SYSTEM /GFS/ MODELING SYSTEM output files, and fix to calculation of precipitation type.
THE formulation of the lowest freezing level height will be changed to use the 2m Temperature rather than surface temperature.
THE new parameters INCLUDE:
1.Sunshine duration field
2.Wilting point field3
3.Field capacity field
The precipitation type algorithM is being modified to prevent excessive sleet production when there is tropopause warming in thE winter
test data will be available at /USE LOWERCASE LETTERS/ except for WRF:
http://wwwt.emc.ncep.noaa.gov/mmb/WRFretro/gfs_para/
DATA DELIVERY TIMING WILL NOT BE IMPACTED BY THIS IMPLEMENTATION. THE GFS DELIVERY TIME WILL NOT CHANGE.
a small increase in DATA VOLUMES is EXPECTED.
THESE CONTENT CHANGES WILL IMPACT ALL DISSEMINATION ROUTES WHICH INCLUDE NOAAPORT…THE NWS PUBLIC FTP SERVER AND THE NCEP PUBLIC FTP SERVER.
DISCLAIMER: NCEP WOULD ENCOURAGE ALL USERS TO ENSURE THEIR DECODERS ARE FLEXIBLE AND ARE ABLE TO ADEQUATELY HANDLE CHANGES IN CONTENT ORDER...PARAMETER FIELDS CHANGING ORDER...CHANGES IN THE SCALING FACTOR COMPONENT WITHIN THE PDS OF THE GRIB FILES AND ALSO ANY VOLUME CHANGES WHICH MAY BE FORTHCOMING. THESE ELEMENTS MAY CHANGE WITH FUTURE NCEP MODEL IMPLEMENTATIONS. NCEP WILL MAKE EVERY ATTEMPT TO ALERT USERS TO THESE CHANGES PRIOR TO ANY IMPLEMENTATIONS.
IF YOU HAVE ANY QUESTIONS CONCERNING THESE CHANGES...PLEASE
CONTACT:
John H. Ward
NCEP...GLOBAL MODELING BRANCH
CAMP SPRINGS MARYLAND
PHONE: 301-763-8000 X7185
EMAIL: john.ward@NOAA.GOV
OR
Hui-Ya chaung
NCEP...GLOBAL MODELING BRANCH
CAMP SPRINGS MARYLAND
PHONE: 301-763-8000 X7219
EMAIL: hui-ya.chaung@NOAA.GOV
THIS AND OTHER NWS TECHNICAL IMPLEMENTATION NOTICES ARE AVAILABLE
ONLINE AT /USE LOWER CASE LETTERS/:
HTTP://WWW.NWS.NOAA.GOV/OM/NOTIF.HTM
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