970730: Early Eta, Meso Eta Changes

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: 970730: Early Eta, Meso Eta Changes
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Wed, 30 Jul 1997 08:33:34 -0600 (MDT)

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NATIONAL TECHNICAL IMPLEMENTATION MESSAGE 97-25
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC 
915 AM EDT WED JUL 30 1997
 
TO:       NATIONAL WEATHER SERVICE /NWS/ EMPLOYEES...OTHER NWS
          CUSTOMERS WHO RECEIVE NWS MODEL OUTPUT
 
FROM:     ROBERT REEVES...SCIENCE DIVISION
          OFFICE OF METEOROLOGY
         
SUBJECT:  CHANGES TO THE OPERATIONAL "EARLY" AND MESO ETA MODELS
          EFFECTIVE AS OF JULY 29 1997
 
AT 1200 UTC 29 JULY 1997 A SERIES OF CHANGES TO THE
POST-PROCESSED OUTPUT FROM THE OPERATIONAL EARLY /48KM/38LEVS/
AND MESO /29KM/50LEV/ ETA WERE IMPLEMENTED. A BRIEF DESCRIPTION
OF EACH CHANGE FOLLOWS:
 
1/ FOUS60-FOUS78 OUTPUT
 
- THE T3 AND T5 VALUES IN THE ETA FOUS60-78 MESSAGES WERE
CORRECTED TO TO REFLECT TEMPERATURES AT APPROXIMATELY THE SAME
PRESSURE LEVEL ABOVE THE MODEL TERRAIN AS THOSE FROM THE NGM
FOUS. FOR EXAMPLE...T5 FOR THE NGM FOUS IS THE TEMPERATURE AT
SIGMA=.7848...WHICH IS ABOUT 215 MB ABOVE THE MODEL SURFACE. IN
THE PREVIOUS VERSION OF THE ETA MODEL...T5 WAS THE TEMPERATURE AT
120-150 MB ABOVE THE MODEL TERRAIN. THE T3 TEMPERATURE IN THE NGM
FOUS IS AT SIGMA=.8967...ABOUT 100 MB ABOVE THE MODEL SURFACE. IN
THE ETA FOUS T3 WAS THE TEMPERATURE AT 60-90 MB ABOVE THE MODEL
SURFACE.
 
2/ GRIDDED OUTPUT
 
- THE CODES WHICH COMPUTE TROPOPAUSE HEIGHT HAVE BEEN MODIFIED TO
CONFORM TO THE WMO DEFINITION OF THE TROPOPAUSE HEIGHT.
 
- AN ERROR IN THE COMPUTATION OF CLOUD WATER ON PRESSURE SURFACES
IN THE EARLY ETA WAS CORRECTED.
 
3/ HOURLY STATION PROFILE OUTPUT
 
- THE STATION LIST USED FOR HOURLY STATION OUTPUT FROM THE ETA
MODEL HAS BEEN MODIFIED TO REFLECT RECENT CHANGES IN RAWINSONDE
STATION LOCATION AND TO CORRECT SOME ERRORS. A SUMMARY OF THESE
CHANGES FOLLOWS:
 
- 74389 /GRAY ME/ ADDED           72606 /PORTLAND ME/ DROPPED
- 72634 /GAYLORD ME/ ADDED
- 72426 /WILMINGTON OH/ ADDED     72421 /CINCINNATI OH/ DROPPED
- 72582 /ELKO NV/ ADDED           72583 /WINNEMUCCA NV/ DROPPED
- 74455 /DAVENPORT IA/ ADDED
- 72364 /SANTA TERESA NM/ ADDED   72270 /EL PASO TX/ DROPPED
- 72376 /FLAGSTAFF AZ/ ADDED      72374 /WINSLOW AZ/ DROPPED
- 72672 /RIVERTON WY/ ADDED       72576 /LANDER WY/ DROPPED
 
THE FOLLOWING STATIONS WERE NOT BEING PLACED AT THE CORRECT
LOCATION:
 
- 71600 /SABLE ISLAND NS/
- 71201 /KEY WEST FL/
- 70308 /ST. PAUL ISLAND AK/
- 91165 /LIHUE  KAUAI  HI/ /48 KM ETA ONLY/
 
IF YOU HAVE ANY QUESTIONS REGARDING THESE CHANGES...CONTACT ERIC
ROGERS AT THE ENVIRONMENTAL MODELLING CENTER AT 301-763-8056.
 
THIS AND OTHER NWS SERVICE CHANGE NOTIFICATIONS ARE AVAILABLE ON
THE NWS OFFICE OF METEOROLOGY/S HOME PAGE... IN THE NOTIFICATION
SECTION.  THE ADDRESS OF THE NOTIFICATION SECTION IS:
 
HTTP://WWW.NWS.NOAA.GOV/OM/NOTIF.HTM   /LOWER CASE/
 
END
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