[nws-changes] 20070821: upgrade NCEP GFS-Fwd: ADMIN NOTICE NOUS41 KWBC]

[Linda Miller]

-------- Original Message --------

480 
NOUS41 KWBC 211130
PNSWSH

TECHNICAL IMPLEMENTATION NOTICE 07-59
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
730 AM EDT TUE AUG 21 2007

TO:       FAMILY OF SERVICES /FOS/ SUBSCRIBERS...NOAA WEATHER 
          WIRE SERVICE /NWWS/ SUBSCRIBERS...EMERGENCY MANAGERS
          WEATHER INFORMATION NETWORK /EMWIN/SUBSCRIBERS...
          OTHER NATIONAL WEATHER SERVICE /NWS/ USERS AND  
          OTHER PARTNERS...NWS EMPLOYEES

FROM:     PAUL HIRSCHBERG
          CHIEF...SCIENCE PLANS BRANCH
          OFFICE OF SCIENCE AND TECHNOLOGY /OST/

SUBJECT:  UPGRADE TO NCEP GLOBAL FORECAST SYSTEM /GFS/:
          EFFECTIVE SEPTEMBER 25 2007

EFFECTIVE TUESDAY SEPTEMBER 25 2007...WITH THE 1200 COORDINATED 
UNIVERSAL TIME /UTC/ RUN...THE NATIONAL CENTERS FOR ENVIRONMENTAL 
PREDICTION /NCEP/ WILL UPGRADE THE GFS POST PROCESSOR.  

THE PRIMARY EFFORT BEHIND THIS UPGRADE WILL BE TO UNIFY THE POST 
PROCESSING CODE FOR THE NORTH AMERICAN MESOSCALE /NAM/ MODEL AND 
THE GFS INTO THE NEW NCEP POST. AFTER THE UPGRADE...BOTH THE NAM 
AND GFS MODELS WILL BE ABLE TO GENERATE FIELDS ORIGINALLY CREATED 
FOR EACH UNIQUE MODEL.  

THE PRIMARY IMPACT TO CUSTOMERS RECEIVING THE GFS WILL BE THAT 
THE DEFAULT PRECIPITATION TYPE ALGORITHM WILL CHANGE FROM THE 
BALDWIN METHOD TO THE DOMINANT PRECIPITATION TYPE. THE DOMINANT 
PRECIPITATION TYPE IS DETERMINED BY TAKING THE PREDICTED 
TEMPERATURE AND MOISTURE PROFILES AND RUNNING THEM THROUGH FIVE 
ALGORITHMS: BALDWIN /NCEP/...REVISED NCEP...RAMER...BOURGOUIN 
...AND AN EXPLICIT MICROPHYSICS ALGORITHM.  AT EACH POINT...THE 
CODE DETERMINES WHICH PRECIPITATION TYPE WAS PREDICTED BY THE 
MAJORITY OF THE ALGORITHMS AND USES THAT AS THE DOMINANT TYPE.  
TIES ARE BROKEN IN FAVOR OF THE MORE DANGEROUS WEATHER 
/ZR>SN>IP>RA/.

IN ADDITION THE SAME ALGORITHMS WILL BE USED TO DERIVE MOST 
FIELDS FOR THE TWO MODELS.

THE PRODUCTS/GRIDS WHICH ARE DISSEMINATED TO NOAAPORT AND/OR THE 
SATELLITE BROADCAST NETWORK /SBN/ WILL NOT BE CHANGED IN VOLUME 
OR CONTENT.

NCEP CENTRAL OPERATIONS IS CURRENTLY RUNNING A REAL-TIME 
PARALLEL. RESULTS FROM THESE PARALLEL RUNS CAN BE VIEWED AT /USE 
LOWER CASE LETTERS/:

HTTP://WWW.NCO.NCEP.NOAA.GOV/PMB/NWPARA/ANALYSIS/ 

IF YOU HAVE ANY QUESTIONS CONCERNING THESE CHANGES...PLEASE 
CONTACT: 

DR MARK IREDELL
NCEP/EMC...CHIEF GLOBAL MODELING BRANCH
CAMP SPRINGS MARYLAND
PHONE: 301 763 8000 X7231
EMAIL: MARK.IREDELL at NOAA.GOV
  OR
KEN CAMPANA
NCEP/EMC...GLOBAL MODELING BRANCH
CAMP SPRINGS MARYLAND
PHONE: 301 763 8000 X7228
EMAIL: KENNETH.CAMPANA at 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

$$