980312: RUC2-17 March 1998-NOUS (fwd)

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: 980312: RUC2-17 March 1998-NOUS (fwd)
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Thu, 12 Mar 1998 12:41:03 -0700 (MST)

741 
NOUS41 KWBC 121855
PNSNMC
 
NATIONAL TECHNICAL IMPLEMENTATION MESSAGE 98-06
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
200 PM EST THU MAR 12 1998
 
TO:       FAMILY OF SERVICES /FOS/ SUBSCRIBERS...NOAA WEATHER
          WIRE SERVICE /NWWS/ SUBSCRIBERS...OTHER NATIONAL
          WEATHER SERVICE /NWS/ CUSTOMERS...NWS EMPLOYEES
 
FROM:     LEROY SPAYD...CHIEF...SCIENCE AND TRAINING CORE
 
SUBJECT   CHANGES TO VERSION 2 OF THE RAPID UPDATE CYCLE (RUC2)
          NUMERICAL WEATHER PREDICTION MODEL...EFFECTIVE MARCH 17
          1998
     
AT 1200 UTC ON MARCH 17...1998...VERSION 2 OF THE RAPID UPDATE
CYCLE (RUC2) WILL BE INTRODUCED INTO OPERATIONS.  THIS NEW
VERSION INCLUDES EXTENSIVE CHANGES AND IMPROVEMENTS TO THE
CURRENT OPERATIONAL RUC WHICH IT IS REPLACING.
     
- RESOLUTION AND COVERAGE - THE HORIZONTAL RESOLUTION WILL
IMPROVE FROM 60-KM TO 40-KM. THE HYBRID-B LEVELS WILL INCREASE
FROM 25 LEVELS TO 40 LEVELS. THE ISENTROPIC SPACING IN MUCH OF
THE TROPOSPHERE HAS BEEN DECREASED FROM 4 K TO 2 K. THE RUC2
DOMAIN COVERS ABOUT 50% MORE AREA THAN THE RUC DOMAIN...MOSTLY BY
EXTENDING COVERAGE TO THE WEST OVER THE PACIFIC OCEAN AND TO THE
SOUTH INTO MEXICO.
     
- FREQUENCY - THE RUN FREQUENCY WILL INCREASE FROM EVERY THREE
HOURS TO HOURLY. THE BACKGROUND FOR EACH ANALYSIS WILL BE THE 1
HOUR FORECAST FROM THE PREVIOUS CYCLE.  A ONE HOUR CYCLE ALLOWS
FOR MORE EXTENSIVE USE OF PROFILER...SURFACE AND VAD DATA...ALL
OF WHICH ARE AVAILABLE AT LEAST HOURLY.  THE DATA CUTOFF WILL BE
18 MINUTES AFTER THE ANALYSIS VALID TIME.  AT 0000 UTC AND 1200
UTC...ANOTHER ANALYSIS WILL BE RUN WITH DATA CUTOFF OF 58 MINUTES
AFTER ANALYSIS VALID TIME TO ALLOW USE OF THE LATER ARRIVING 
RAWINSONDE DATA.  THE FORECAST IS RUN FROM THAT ANALYSIS.
     
- FORECAST LENGTH - FORECASTS WILL BE PRODUCED OUT TO 12 HOURS
EVERY THREE HOURS AND OUT TO 3 HOURS AT THE INTERIM CYCLES.
     
- MODEL CHANGES - SIGNIFICANT IMPROVEMENTS HAVE BEEN MADE TO THE
FORECAST MODEL...INCLUDING IMPROVED SURFACE PHYSICS...SNOW
PHYSICS AND THE USE OF DAILY LAKE-SURFACE AND SEA-SURFACE
TEMPERATURE AND SNOW/ICE COVER FIELDS.  EXPLICIT CLOUD/MOISTURE
MICROPHYSICS ARE NOW INCLUDED ALONG WITH AN ATMOSPHERIC RADIATION
PACKAGE.  THE CONVECTIVE PARAMETERIZATION HAS ALSO BEEN IMPROVED.
     
- MORE EXTENSIVE AND DETAILED INFORMATION ON THE DIFFERENCES
BETWEEN RUC AND RUC2 CAN BE OBTAINED AT THE FOLLOWING WEB SITE:
 
HTTP://MAPS.FSL.NOAA.GOV   /LOWER CASE/
 
 
LINKS TO INFORMATION AND RESULTS FROM THE RECENT FIELD EVALUATION
OF RUC2 CAN BE FOUND AT THAT SITE AS WELL. ALSO...A DRAFT VERSION
OF THE TECHNICAL PROCEDURES BULLETIN ON THE RUC2 UPGRADE CAN BE
FOUND AT
 
HTTP://MAPS.FSL.NOAA.GOV/RUC2.TPB.HTML    /LOWER CASE/
     
- MOST OF THE OUTPUT FROM THE RUC2 WILL BE AVAILABLE IN GRIB
FORMAT ON A SUBSET OF GRID #212...A 40KM LAMBERT-CONFORMAL GRID. 
PREVIOUSLY...THE RUC WAS AVAILABLE ON THE 80KM LAMBERT-CONFORMAL
GRID (#211). THE 80KM...GRID #211 OUTPUT PREVIOUSLY SUPPLIED TO
FAMILY OF SERVICES SUBSCRIBERS WILL CONTINUE TO BE PRODUCED.
 
END