NOCN03 CWAO 142228 GENOT ADMIN NO. 015 LA VERSION FRANCAISE DE CE GENOT EST NO. 016 THE FRENCH VERSION OF THIS GENOT IS NO. 016 UPGRADE TO THE HIGH RESOLUTION DETERMINISTIC PREDICTION SYSTEM (HRDPS) AT THE CANADIAN METEOROLOGICAL CENTRE (CMC). ON TUESDAY DECEMBER 15 2015, STARTING WITH THE 12 UTC RUN, THE METEOROLOGICAL SERVICE OF CANADA'S CANADIAN METEOROLOGICAL CENTRE CMC) WILL IMPLEMENT CHANGES TO THE EXPERIMENTAL HIGH RESOLUTION DETERMINISTIC PREDICTION SYSTEM (HRDPS). FOR THE PAN-CANADIAN DOMAIN, THE CURRENT VERSION 4.0.0 (HEREAFTER CALLED HRDPS-4.0.0) WILL BE REPLACED BY THE NEW VERSION OF THE HRDPS, THAT IS VERSION 4.1.0 (HEREAFTER CALLED HRDPS-4.1.0). 1. GENERAL DESCRIPTION 1.1 GEM MODEL VERSION HRDPS-4.1.0 USES GEM MODEL VERSION 4.7.0. MANY OF THE CHANGES TO THE MODEL, FROM THAT USED BY HRDPS-4.0.0, ARE RELATIVELY MINOR. HOWEVER, THERE ARE FOUR SIGNIFICATIVE CHANGES FOR THE HRDPS-4.1.0 AS FOLLOWS: (1) THE USE OF AN IMPLICIT DEEP CONVECTION SCHEME KAIN AND FRITCH. (2) A CORRECTION FOR FREEZING RAIN EVENTS THAT WERE LARGELY UNDER- ESTIMATED IN THE HRDPS-4.0.0. (3) A CORRECTION FOR RAIN ON SNOW EVENTS (IMPLEMENTED IN FEBRUARY 2015). (4) SOME MODIFICATIONS AT THE SNOW ANALYSIS PROVIDED BY THE SURFACE ASSIMILATION SYSTEM (CALDAS). 1.2 OVERVIEW OF SYSTEM HRDPS-4.1.0 PROVIDES A DETERMINISTIC FORECAST OF THE GEM MODEL ON A LIMITED AREA MODEL (LAM) DOMAIN, WITH A HORIZONTAL GRID SPACING OF APPROXIMATELY 2.5 KM. THE COMPUTATIONAL DOMAIN COVERS A LARGE PORTION OF CANADA, EXTENDING WEST-TO-EAST FROM THE PACIFIC TO THE ATLANTIC OCEANS, COVERING MUCH OF THE TERRITORIES NORTHWARD, AND EXTENDING SOUTHWARD TO COVER MUCH OF THE NORTHERN US. AS IN THE PREVIOUS VERSION (HRDPS-4.0.0), THE HRDPS-4.1.0 INVOLVES A 2-WAY COUPLING BETWEEN THE ATMOSPHERIC MODEL AND THE CANADIAN LAND DATA ASSIMILATION SYSTEM (CALDAS). THESE 2 SUB-SYSTEMS EXCHANGE DATA EVERY 6 HOURS IN A CONTINUOUS CYCLE. THE SURFACE INITIAL CONDITIONS (ICS) ARE PROVIDED TO THE ATMOSPHERIC MODEL BY CALDAS, WHICH IN TURN USES DIFFERENT FIELDS PREDICTED BY THE ATMOSPHERIC MODEL DURING THE FIRST 6 HOURS OF THE MODEL 48-HOUR FORECAST (SURFACE PRESSURE, PRECIPITATION, RADIATIVE FLUXES, SURFACE TEMPERATURE, HUMIDITY AND WINDS) TO PRODUCE NEW SURFACE FIELDS EVERY 6 HOURS. NOTE THAT THE SAME 48-HOUR MODEL INTEGRATION IS USED BOTH IN THE COUPLED CYCLE AND TO PROVIDE THE ATMOSPHERIC FORECAST. FOR A GIVEN MODEL INTEGRATION, THE UPPER-AIR ICS ARE PROVIDED TO THE ATMOSPHERIC MODEL BY THE REGIONAL DETERMINISTIC PREDICTION SYSTEM (RDPS) ANALYSIS, AND THE LATERAL BOUNDARY CONDITIONS ARE PROVIDED BY THE RDPS FORECAST. ALSO, THE MICROPHYSICS HYDROMETEOR FIELDS (CLOUDS AND PRECIPITATION FROM THE MICROPHYSICS SCHEME) ARE RECYCLED. THIS IS DONE BY PROVIDING TO THE ATMOSPHERIC MODEL AS INITIAL MICROPHYSICS HYDROMETEOR FIELDS THE 6 HOUR FORECAST OF THE PREVIOUS MODEL INTEGRATION. 1.3 FORECAST FREQUENCY AND PERIOD HRDPS-4.1.0 PROVIDES DETERMINISTIC 48 HOUR FORECASTS FOUR TIMES PER DAY BEGINNING AT THE SYNOPTIC HOURS 00, 06, 12, AND 18 UTC. 1.4 HRDPS FOR THE ARCTIC AND LANCASTER DOMAINS FOR THE ARCTIC AND LANCASTER DOMAINS, WHICH ARE NOT COVERED BY THE DOMAIN OF HRDPS-4.1.0, HRDPS-3.0.4 WILL CONTINUE TO BE RUN ONCE PER DAY WITH NO CHANGE. 2. EVALUATION SEVERAL FORECAST FIELDS FROM HRDPS-4.1.0 WERE OBJECTIVELY EVALUATED AGAINST OBSERVATIONS USING STANDARD SKILL SCORES AND COMPARED TO CORRESPONDING EVALUATIONS OF THE RDPS FOR THE SAME SET OF CASES. THE CASE SET CONSISTED OF 40 WINTER AND 40 SUMMER CASES FROM 2011, SEPARATED BY 36 HOURS TO ENSURE METEOROLOGICAL INDEPENDENCE BETWEEN THE CASES. THE FIELDS EVALUATED INCLUDED SCREEN-LEVEL TEMPERATURE, HUMIDITY, WIND SPEED, FRACTIONAL CLOUD COVER, 6 HOURLY PRECIPITATION, UPPER-AIR TEMPERATURE, HUMIDITY, WINDS, AND GEOPOTENTIAL HEIGHT. OVERALL, THE PERFORMANCE OF THE HRDPS-4.1.0 IS SIMILAR TO THAT OF THE PREVIOUS SYSTEM FOR THE OBJECTIVE EVALUATION OF UPPER AIR VERTICAL SOUNDINGS AND SURFACE STATIONS. THE MAIN DIFFERENCES ARE NOTED FOR THE SUMMER PRECIPITATION BECAUSE THE MODEL AS LESS TENDENCY TO PRODUCE STRONG EVENTS AT THE END OF THE DAY DUE TO THE USE OF A DEEP CONVECTION SCHEME. ALSO, THE OBSERVED PROBLEMS FOR THE SNOW ANALYSIS (TOO RAPID MELTING DURING THE SPRING AND OCCURANCE OF THIN SNOW LAYER DURING THE FALL) AND THE UNDER-ESTIMATION OF FREEZING RAIN ARE LARGELY REDUCED WITH THE HRDPS-4.1.0. 3. AVAILABILITY OF PRODUCTS HRDPS-4.1.0 OUTPUT ARE AVAILABLE FOUR TIMES PER DAY, EXCEPT ONCE A DAY FOR THE ARCTIC AND LANCASTER DOMAINS WHICH ARE UNCHANGED. FOR MORE DETAILS PLEASE REFER TO THE TECHNICAL NOTE AVAILABLE VIA THE FOLLOWING LINK (SEE THE ENTRY REFERRING TO HRDPS-4.1.0): HTTP://COLLABORATION.CMC.EC.GC.CA/CMC/CMOI/PRODUCT_GUIDE/DOCS/ CHANGES_E.HTML (THE LINK MUST BE TYPED ON ONE LINE IN LOWERCASE). FOR QUESTIONS REGARDING HRDPS-4.0.0 AND ASSOCIATED PRODUCTS, OR OTHER SPECIFIC QUESTIONS CONCERNING THIS OPERATIONAL IMPLEMENTATION, YOU CAN WRITE TO (USING LOWER CASE): PRODUCTION-INFO(AT)CMC.EC.GC.CA GRIMES / ADM-MSC / SMA-SMC END