20010724: meso eta - ADMIN NOTICE NOUS41 KWBC (fwd)

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: 20010724: meso eta - ADMIN NOTICE NOUS41 KWBC (fwd)
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Tue, 24 Jul 2001 09:48:52 -0600

922
NOUS41 KWBC 241539
PNSWSH

PUBLIC INFO. STATEMENT ... TECHNICAL INFORMATION NOTICE 01-19
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
1145 AM EDT TUE JUL 24 2001

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

FROM:     PAUL NIPKO
          ACTING CHAIR...COMMITTEE ON ANALYSIS AND FORECAST
          TECHNIQUE IMPLEMENTATION /CAFTI/

SUBJECT:  CHANGES IMPLEMENTED IN THE NATIONAL CENTERS FOR
          ENVIRONMENTAL PREDICTION /NCEP/ OPERATIONAL MESO ETA
          MODEL SYSTEM...EFFECTIVE JULY 24 2001 AT 1200 UTC

...THE FOLLOWING CHANGES HAVE NO IMPACT ON NOAA WEATHER WIRE
SERVICE OR EMWIN SUBSCRIBERS...

AT 1200 UTC 24 JULY 2001....THE FOLLOWING CHANGES TO THE
OPERATIONAL MESO ETA MODEL WERE IMPLEMENTED:

- THE ETA 3-DIMENSIONAL VARIATIONAL /3DVAR/ ANALYSIS WAS
MODIFIED...BY INTRODUCING A NEW ALGORITHM TO IMPROVE THE BALANCE
BETWEEN MASS AND WIND ANALYSES... BY PERFORMING THE ANALYSIS ON
THE ETA VERTICAL COORDINATE SURFACES INSTEAD ON PRESSURE
SURFACES... AND BY INCREASING THE HORIZONTAL RESOLUTION OF THE
INTERNAL ANALYSIS GRID

- ASSIMILATION OF HOURLY ANALYSES OF OBSERVED PRECIPITATION
DURING THE ETA DATA ASSIMILATION SYSTEM /EDAS/ RUN:  THIS WILL
CORRECT PRECIPITATION BIASES DURING THE PRE-FORECAST ASSIMILATION
PERIOD...IMPROVE THE SOIL MOISTURE FIELD...AND IMPROVE THE MESO
ETA MODEL/S SHORT-TERM PRECIPITATION FORECAST.  THE HOURLY NCEP
NATIONAL 4-KM PRECIPITATION ANALYSIS IS USED DURING THE EDAS...
BASED ON 2500 HOURLY RAIN GAUGES AND HOURLY PRECIPITATION
ESTIMATES FROM THE WSR-88D RADARS

- THE LAND-SURFACE PHYSICS SCHEME IN THE MESO ETA MODEL WAS
UPGRADED.  DURING THE COLD SEASON:  IMPROVED SHELTER TEMPERATURES
OVER PATCHY SNOWCOVER...NEW STATE VARIABLES /FROZEN SOIL...
VARIABLE SNOWPACK DENSITY/...AND NEW MAXIMUM SNOW ALBEDO
DATABASE.  DURING THE WARM SEASON:  IMPROVED NEAR-SURFACE
SENSIBLE AND DEW POINT TEMPERATURES...DUE TO IMPROVED
FORMULATIONS OF BARE SOIL EVAPORATION AND SOIL THERMAL
CONDUCTIVITY

THIS CHANGE WAS APPROVED AT THE MAY 24 2001 MEETING OF THE
COMMITTEE ON ANALYSIS AND FORECAST TECHNIQUE IMPLEMENTATION
/CAFTI/.  A COPY OF THE PRESENTATION MADE AT THAT MEETING IS
AVAILABLE ONLINE AT /USE LOWER CASE/:

FTP://FTP.NCEP.NOAA.GOV/PUB/EMC/WD20ER/CAFTIMAY01/V3_DOCUMENT.HTM

VERIFICATION STATISTICS FOR BOTH THE REAL-TIME PARALLEL TESTS AND
RETROSPECTIVE TESTS OF THE FULL CHANGE PACKAGE CAN BE FOUND AT
/USE LOWER CASE/:

HTTP://WWW.EMC.NCEP.NOAA.GOV/MMB/MMBPLL/SPRING2001/STATS/BUNDLE.HTML

MORE DETAILS CAN BE FOUND IN  NWS TECHNICAL PROCEDURES BULLETIN
NUMBER 479 AT /USE LOWER CASE/:

     HTTP://WWW.EMC.NCEP.NOAA.GOV/MMB/MMBPLL/SPRING2001/TPB/

NO CHANGES TO ANY OF THE STANDARD ETA MODEL GRIDS OR PRODUCTS
AVAILABLE FROM THE FAMILY OF SERVICES...THE AWIPS SATELLITE
BROADCAST NETWORK...OR FROM THE OSO FILE SERVER WERE MADE WITH
THIS IMPLEMENTATION.

IF YOU HAVE ANY QUESTIONS ABOUT THESE CHANGES TO THE ETA
MODEL...PLEASE CONTACT ONE OF THE FOLLOWING PEOPLE AT NCEP IN
CAMP SPRINGS MARYLAND:

     ERIC ROGERS
     PHONE:  301-763-8000 EXT. 7227
     E-MAIL: EROGERS@xxxxxxxxxxxxx

     OR

     GEOFF DIMEGO
     PHONE:  301-763-8000 EXT. 7221
     E-MAIL: GDIMEGO@xxxxxxxxxxxxx

THIS AND OTHER NATIONAL TECHNICAL INFORMATION NOTICES ARE
AVAILABLE ON THE INTERNET AT /USE LOWER CASE/:

          HTTP://WWW.NWS.NOAA.GOV/OM/NOTIF.HTM

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