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IMPLEMENTATION OF A REAL TIME SHORT RANGE ENSEMBLE FORECAST (SREF) SYSTEM AT NCEP. N C E P. Steve Tracton and Jun Du NCEP/EMC. Where the nation’s climate and weather services begin. NON REAL-TIME SREF RAN EXPERIMENTALLY FROM APRIL 2000 – APRIL 2001
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IMPLEMENTATION OF A REAL TIME SHORT RANGE ENSEMBLE FORECAST (SREF) SYSTEM AT NCEP N C E P Steve Tracton and Jun Du NCEP/EMC Where the nation’s climate and weather services begin
NON REAL-TIME SREF RAN EXPERIMENTALLY FROM APRIL 2000 – APRIL 2001 • CASE STUDIES, ANECDOTAL EVIDENCE SUGGESTED SREF POTENTIALLY VALUABLE FOR OPERATIONAL FORECASTING • PQPF • WINTER STORMS • CONVECTIVE OUTLOOKS • STORM TRACKS • AVIATION WEATHER • EXTREME/RARE EVENTS MOTIVATION
BUT, EXPERIMENTAL SYSTEM RAN ON DEVELOPMENT SIDE OF IBM – NOT RELIABLY AVAILABLE (DEVELOPER SUPPORT ONLY) RAN IN DELAYED MODE – NOT SUFFICIENTLY TIMELY FOR THOROUGH FORECASTER EVALUATION (7:30Z FOR 00Z RUNS, 19:30Z FOR 12Z RUNS) PRODUCTS AVAILABLE ON WEB ONLY – NOT NAWIPS • SYSTEM JUDGED SUFFICIENTLY MATURE FOR REAL TIME TEST AND EVALUATION • NCEP SERVICE CENTERS REQUIRESREF PRODUCTS RELIABLY, TIMELY AND ON NAWIPS BEFORE FULL IMPLEMENTATION CAN BE ENDORSED MOTIVATION (CONT.)
JAN 2000 SNOWSTORM: 12 HR PRECIP FROM 00Z 24JAN VT 12Z 25JAN.25:
RTT&E MODE IS A DESIGNATION THAT INDICATES: • INTERNAL NCEP IMPLEMENTATION • RUN ON THE PRODUCTION IBM WITH NCEP/NCO PRODUCTION STANDARDS AND SUPPORT • STEP ABOVE “PARALLEL” RUNS ON DEVELOPMENT IBM • PRODUCTS NOT (YET) SANCTIONED NOR DISTRIBUTED BY THE NWS OPERATIONAL • IN THIS SENSE, SREF COMPARABLE IN STATUS TO CURRENT RUNS OF THE NESTED 10KM MESO ETA (“THREATS” RUNS) • RUN IN EXISTING WINDOWS OF THE IBM PRODUCTION SUITE AND DOES NOT IMPACT ANY OTHER OPERATIONAL JOBS REAL TIME TEST AND EVALUATION (RTT&E)
10 MEMBERS (5 ETA, 5 RSM) • 48 KM RESOLUTION • FULL ETA DOMAIN • RUN TWICE DAILY; FROM 09Z AND 21Z TO 63 HOURS PRODUCTS AVAILABLE ABOUT SAME TIME AS NEXT OPERATIONAL 12Z AND 00Z ETA RUNS • “REGIONAL BREEDING” FOR INITIAL CONDITION PERTURBATIONS • LATERAL BOUNDARY CONDITIONS FROM 9 HR OLD GLOBAL ENS SREF SYSTEM
RTT&E PHASE I (JUNE 5, 2001) • SREF OFFICIALLY INTRODUCED INTO NCEP PRODUCTION SUITE • GRIB AND GEMPAK “THINNED” GRIDDED DATA – ONE FILE PER MEMBER – AVAILABLE ON NCODAS FOR SERVICE CENTER ACCESS (FTP* OF GRIB FILES FOR EXTERNAL USERS); THINNED >> Output at all times at 3-hour intervals, but for selected parameters and levels only (same as global ensemble +) Z: 1000, 850, 700, 500, 250 : U,V: 850, 500, 250 PMSL: T: 2M, 850, 700, Tmax, Tmin RH: 850, 700: ABSV: 500, 250 PRECIP: LI, CAPE, CIN • SAME PRODUCT SET AND ACCESS AS PREVIOUS NON-REAL TIME SYSTEM (EXCEPT OUTPUT AT 3 HOUR INTERVALS) • MOSTLY WEB BASED (http://lnx48.wwb.noaa.gov/SREF/SREF.html) • NCEP SERVICE CENTERS’ CONCENSUS “BASE” SET • ENSEMBLE MEANS, SPREAD, SPAGHETTI CHARTS, PROBABILITES • SELECTED PARAMETERS/LEVELS
RTT&E PHASE II (~ MID AUGUST 2001) • OFFICIAL BASE PRODUCT SET – SAME AS ON WEB - GENERATED ON IBM • COMPONENT OF SREF PRODUCTION SUITE • PRODUCTS IN GRIB FORMAT WITH APPROPRIATE ENSEMBLE SPECIFIC GRIB EXTENSIONS (FTP ACCESS FOR EXTERNAL USERS*) • * FTP SITE: ftp.ncep.noaa.gov; • LOGIN: anonymous; PASSWD: your email address; DIRECTORY: pub/data1/sref/sref.yymmdd).
WHAT FOLLOWS BEGINNING OF REAL TIME T&E? • EDUCATION AND TRAINING IN USE OF SREF AT SERVICE CENTERS; • “MISSIONARY WORK” – ON SITE VISITS (TRAVEL FUND LIMITED) WEB BASED TUTORIALS/ “VISIT VIEW” • PRODUCT DEVELOPMENT (BEYOND BASE SET) • COMMON TO ALL SERVICE CENTERS (E.G., STD PARAMETER METEOGRAMS): FOLLOW LEAD OF MET OFFICE EXPERIENCE • SERVICE CENTER SPECIFIC (E.G., “SPAGHETTI” HODOGRAPHS) STATISTICAL POST PROCESSING (E.G., CALIBRATE PROBABILITIES, ENSEMBLE MOS) • NCEP SOO’S, IN COLLABORATION WITH EMC, RESPONSIBLE FOR REFINEMENTS TO COMMON PRODUCT SUITE AND DEVELOPMENT AND TESTING OF NEW SPECIALIZED PRODUCTS • ISSUES: • NEED TO DEFINE PROCESS FOR INTRODUCING NEW COMMON PRODUCTS INTO PRODUCTION SUITE • CENTER SPECIFIC PRODUCTS: NEED TO DETERMINE WHETHER TO RUN IN PRODUCTION, ON IBM WITH PRIORITY, OR RUN LOCALLY
WHAT FOLLOWS BEGINNING OF REAL TIME T&E?(CONT) • EVALUATION – SYSTEM PERFORMANCE AND VALUE • OBJECTIVE VERIFICATION (E.G., RMS ERRORS, RANKED PROBABILITY SCORE, TALAGRAND HISTOGRAMS, RELIABILITY DIAGRAMS) • SUBJECTIVE – USER FEEDBACK • NCEP SERVICE CENTERS (HPC, SPC, TPC, MPC) • FIELD (SELECTED “BETA” SITES) • SYSTEM DEVELOPMENT • PARALLEL TEST SYSTEM ON DEVELOPMENT SIDE OF IBM • PERTURB PHYSICS ? • ADDITIONAL MEMBERS ? • ADDITIONAL MODELS (E.G., RUC) ? • INCREASED RESOLUTION ? • TRANSITION TO WRF (LONGER TERM)
WHAT FOLLOWS BEGINNING OF REAL TIME T&E?(CONT) • SYSTEM DEVELOPMENT PARALLEL TEST SYSTEM ON DEVELOPMENT SIDE OF IBM PERTURB PHYSICS ? MORE MEMBERS ? ADDITIONAL MODELS (E.G., RUC) ? INCREASED RESOLUTION ? TRANSITION TO WRF (LONGER TERM)
ISSUES FOLLOWING BEGINNING OF REAL TIME T&E • RESOURCES: CURRENTLY ONLY ONE FULL TIME PERSON DEDICATED TO SREF (NO BACKUP) EXPLORING FAA FUNDING, COMET (UMD STUDENT) OTHER ? LIMITED WINDOW AVAILABLE ON PROD SIDE OF IBM MOTTO: “DO NOT LET WHAT YOU CANNOT DO INTERFERE WITH WHAT YOU CAN DO” SET PRIORITIES W.R.T. ITEMS ON PREVIOUS SLIDE GIVEN AVAILABLE RESOURCES!!!! • OPERATIONAL IMPLEMENTATION: TARGET: MID 2002 (MAY 2001 SYSTEM, PENDING DECISIONS ON ALTERNATIVES) COUNTDOWN ON “MODEL PRE-IMPLEMNTATION CHECK LIST” FOLLOWED REQUIRE NWSHQ TO PLAN AND EXECUTE BROADER (THAN JUST NCEP) PROGRAM FOR TRAINING, COMMUNICATIONS, PRODUCT DISSEMINATION (AWIPS), ETC.
