20060317: ncep eta to non-hydrostatic model - ADMIN NOTICE NOUS41 KWBC (fwd)

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: 20060317: ncep eta to non-hydrostatic model - ADMIN NOTICE NOUS41 KWBC (fwd)
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Fri, 17 Mar 2006 09:34:35 -0700

427
NOUS41 KWBC 171620
PNSWSH

TECHNICAL IMPLEMENTATION NOTICE 05-68...AMENDED
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
1120 AM EST FRI MAR 17 2006

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

SUBJECT:  UPDATED: REPLACEMENT OF NCEP ETA MODEL WITH THE NON-
         HYDROSTATIC MESOSCALE MODEL POSTPONED TO JUNE 13 2006

REFER TO: TECHNICAL IMPLEMENTATION NOTICE /TIN/ 05-68 TRANSMITTED
         ON OCTOBER 3 2005

AMENDED TO DELAY THE EFFECTIVE DATE FOR THE REPLACEMENT OF THE
NCEP ETA MODEL WITH THE NON-HYDROSTATIC MESOSCALE MODEL FROM
MARCH 28 2006 UNTIL JUNE 13 2006.

THE ORIGINAL NOTICE...WITH EXPANDED INFORMATION /DESCRIPTION OF
DIFFERENCES BETWEEN SYSTEMS AND ADDITIONAL ONLINE RESOURCES/...
AND REVISED DATES...IS GIVEN BELOW:

ON JUNE 13 2006...BEGINNING WITH THE 1200 COORDINATED UNIVERSAL
TIME /UTC/ RUN...THE NATIONAL CENTERS FOR ENVIRONMENTAL
PREDICTION /NCEP/ WILL REPLACE THE FORECAST MODEL CURRENTLY RUN
IN THE NORTH AMERICAN MESOSCALE SYSTEM.  THE 12 KM HORIZONTAL
RESOLUTION ETA MODEL IS CURRENTLY USED IN THIS SYSTEM. THE MODEL
WILL BE REPLACED WITH A 12 KM HORIZONTAL RESOLUTION WEATHER
RESEARCH AND FORECASTING /WRF/ VERSION OF THE NON-HYDROSTATIC
MESOSCALE MODEL /NMM/.

THE DIFFERENCES BETWEEN THE NCEP ETA AND WRF NMM SYSTEMS ARE AS
FOLLOWS:

1. MODEL CHANGES

- REPLACE ETA PREDICTION MODEL WITH WRF VERSION OF THE NON-
HYDROSTATIC MESO MODEL (WRF-NMM)
- EXTENDED MODEL TOP PRESSURE FROM 25 MB TO 2 MB
- REPLACE ETA STEP-MOUNTAIN VERTICAL COORDINATE WITH NMM HYBRID
SIGMA-PRESSURE VERTICAL COORDINATE
- REFINED/RETUNED NUMEROUS ASPECTS OF THE ETA MODEL PHYSICS FOR
USE IN THE NMM

2. ANALYSIS CHANGES

- REPLACE ETA 3DVAR ANALYSIS SYSTEM WITH THE NEW UNIFIED GSI
ANALYSIS SYSTEM THAT HAS BEEN ADAPTED FOR APPLICATION TO THE WRF-
NMM
- REPLACE NEXRAD LEVEL II.5 DATA IN ETA 3DVAR WITH NEXRAD LEVEL
II RADIAL WIND DATA IN GSI
- GSI USES BACKGROUND ERRORS BASED ON WRF-NMM FORECASTS...ETA
3DVAR USED BACKGROUND ERRORS BASED ON GFS FORECASTS
- USE OF DYNAMICALLY RETUNED OBSERVATIONAL ERRORS

3. DATA ASSIMILATION CHANGES

- IMPLEMENT DIRECT USE OF OBSERVED PRECIPITATION ANALYSIS VALUES
IN THE LAND-SURFACE PHYSICS MODULES. THIS REPLACES PRIOR USE OF
NUDGING /TO PRECIPITATION AND GOES CLOUD TOP PRESSURES/

THERE WILL BE NO NAME CHANGES ASSOCIATED WITH THIS MODEL
REPLACEMENT.  PRODUCTS AVAILABLE ON NOAAPORT WILL ALSO REMAIN
UNALTERED WITH THIS CHANGE.  ALL CURRENT NAM GUIDANCE PRODUCTS
WILL CONTINUE TO BE AVAILABLE AT THE SAME TIME IN THEIR CURRENT
RESOLUTIONS AFTER THIS CHANGE IS IMPLEMENTED.

NCEP CENTRAL OPERATIONS /NCO/ HAS BEGUN PARALLEL TESTING OF THE
NAM WITH THE WRF NMM MODEL.  THE OUTPUT FROM THIS PARALLEL RUN
WILL BE AVAILABLE BEGINNING THE WEEK OF MARCH 20 AT THE FOLLOWING
FTP LOCATION /USE LOWER CASE LETTERS/:

FTP://FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/NAM/PARA/

AND AT AN ADDITIONAL FTP LOCATION /USE LOWER CASE LETTERS AND
FOLLOW URL WITH DATE /YYYYMMDD/:

FTP://FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/NAWIPS/PARA/NAM

ADDITIONAL INFORMATION ON THIS CHANGE... INCLUDING PARALLEL DATA
AVAILABILITY...FTP SERVER PRODUCT CHANGES...AND OTHER SCIENTIFIC
INFORMATION CAN BE FOUND AT /USE LOWER CASE LETTERS/:

HTTP://WWW.NCO.NCEP.NOAA.GOV/PMB/CHANGES/

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

GEOFF DIMEGO
NCEP...MESOSCALE MODELING BRANCH
CAMP SPRINGS MARYLAND
PHONE: 301 763 8000 X7221
EMAIL: GEOFF.DIMEGO@xxxxxxxx

OR

ERIC ROGERS
NCEP...MESOSCALE MODELING BRANCH
CAMP SPRINGS MARYLAND
PHONE: 301 763 8000 X7227
EMAIL: ERIC.ROGERS@xxxxxxxx

OR

BRENT GORDON
NCEP...PRODUCTION MANAGEMENT BRANCH
CAMP SPRINGS MARYLAND
PHONE: 301 763 8000 X7193
EMAIL: BRENT.GORDON@xxxxxxxx

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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