980403: RUC2 update-NOUS (fwd)

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: 980403: RUC2 update-NOUS (fwd)
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Fri, 3 Apr 1998 12:10:51 -0700 (MST)

436 
NOUS41 KWBC DDHHMM AMD   
 
NATIONAL TECHNICAL IMPLEMENTATION MESSAGE 98-06...UPDATED...
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
1240 PM EST THU APR 3 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   VERSION 2 OF THE RAPID UPDATE CYCLE (RUC2) NUMERICAL
          WEATHER PREDICTION MODEL...EFFECTIVE MONDAY APRIL 6
          1998...NEW DATE AFTER POSTPONMENT ON MARCH 17 1998
     
AT 1200 UTC ON APRIL 6 1998...VERSION 2 OF THE RAPID UPDATE CYCLE
(RUC2) WILL BE INTRODUCED INTO OPERATIONS...AFTER A POSTPONMENT
FROM MARCH 17 1998.  THIS NEW VERSION INCLUDES EXTENSIVE CHANGES
AND IMPROVEMENTS TO THE CURRENT OPERATIONAL RUC WHICH IT IS
REPLACING.  EACH OF THESE CHANGES AND IMPROVEMENTS  ARE DESCRIBED
BELOW.  
 
...CHANGES AND IMPROVEMENTS...
 
- 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).
 
NOTES ON OUTPUT:
 
     THE GRID #212 OUTPUT /UPDATED EVERY HOUR...AS MENTIONED
     BELOW/ IS ONLY AVAILABLE THROUGH FILE TRANSFER PROTOCOL FROM
     THE NWS OFFICE OF SYSTEMS OPERATIONS SERVER /IP ADDRESS
     140.90.6.103/. 
 
     THE 80KM...GRID #211 OUTPUT WILL CONTINUE TO BE SUPPLIED TO
     FAMILY OF SERVICE/S HIGH RESOLUTION DATA SERVICE AS
     BEFORE...EVERY THREE HOURS.  HOWEVER...THE IMPROVEMENTS
     INHERENT IN RUC2 SHOULD PROVIDE IMPROVED ACCURACY TO THIS
     OUTPUT.
 
- 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/
     
END