GEM Upgrade

[hm8]

FWIW

http://dd.weatheroffice.ec.gc.ca/bulletins/alphanumeric/20121002/NO/CWAO/17/NOCN03_CWAO_021644___00044

[Amped]

IN DEVELOPMENT PHASE

THE RDPS-300 WAS TESTED EXTENSIVELY. MANY CYCLES, EACH COVERING AT

LEAST TWO SUMMER MONTHS AND TWO WINTER MONTHS WERE PERFORMED AND

EVALUATED DURING THE DEVELOPMENT PHASE. FOR THE FINAL TESTS,

OBJECTIVE VERIFICATION OF UPPER AIR AND SURFACE FIELDS AGAINST

RADIOSONDE DATA SHOWED A VERY SIGNIFICANT IMPROVEMENT AT ALL

FORECAST LEAD-TIMES. THIS WAS GENERALLY TRUE FOR ALL SEASONS

TESTED AND FOR ALL REGIONS AND VARIABLES. THE ONLY - SLIGHT -

DETERIORATION SEEN WAS WITH THE WINTERTIME COLD BIAS NEAR THE

SURFACE, WHICH WE WERE NOT ABLE TO ELIMINATE. THIS IS NOT

CONSIDERED A MAJOR PROBLEM WHEN COMPARED TO THE IMPROVEMENTS OF THE

RDPS-300.

3.2 IN PARALLEL RUN

THE NEW SYSTEM WAS ALSO RUN IN PARALLEL WITH THE OPERATIONAL SYSTEM

FROM MID-JUNE TO THE END OF SEPTEMBER 2012.

3.2.1 OBJECTIVE EVALUATION

THE OBJECTIVE EVALUATION OF THIS PARALLEL RUN COMPARED TO THE

OPERATIONAL SYSTEM SHOWED IMPROVEMENTS SIMILAR TO THOSE OBSERVED

DURING THE DEVELOPMENT PHASE.

3.2.2 SUBJECTIVE EVALUATION

A SUBJECTIVE EVALUATION WAS DONE ON A DAILY BASIS BY OPERATIONAL

METEOROLOGISTS AT CMC. WHEN A DIFFERENCE IN MASS FIELD FORECASTS

WAS FOUND BETWEEN THE TWO SYSTEMS (ABOUT 30% OF THE TIME), A

PREFERENCE FOR THE NEW SYSTEM WAS EXPRESSED IN A RATIO OF ABOUT

2:1. DIFFERENCES WERE MORE FREQUENT ALONG THE ATLANTIC COAST THAN

THE PACIFIC. HOWEVER, WHEN THE SYSTEMS DIFFERED, PREFERENCE FOR

THE NEW SYSTEM WAS STRONGER FOR THE PACIFIC AREA THAN FOR EASTERN

NORTH AMERICA AND OVER THE ATLANTIC. FOR PRECIPITATION FORECASTS

THE SIGNAL WAS NEUTRAL OR SLIGHTLY IN FAVOUR OF THE NEW SYSTEM,

SIMILAR TO THE FINDINGS OF THE OBJECTIVE SCORES. METEOROLOGISTS

OBSERVED A NOTICEABLE INCREASE IN THE DETAIL OF PRECIPITATION

PATTERNS, ESPECIALLY WITH ORGANIZED MESOSCALE CONVECTION. STORMS

OF TROPICAL ORIGIN DID NOT VENTURE OFTEN INTO OUR FORECAST AREAS,

THOSE THAT DID WERE BETTER FORECAST BY THE RDPS-300. IT WAS FOUND

THAT THEIR CENTRAL PRESSURE WAS LESS DEEP AND THEIR SPATIAL EXTENT

WAS BETTER DEFINED THAN WITH THE OPERATIONAL RDPS. IN PARTICULAR,

RDPS-300 PROVIDED A BETTER FORECAST OF HURRICANE LESLIE, WHICH

AFFECTED CONSIDERABLY NEWFOUNDLAND ON SEPTEMBER 11, 2012.

[

3.3 PERFORMANCE OF DEPENDENT SYSTEMS

3.3.1 UMOS

VERIFICATION OF UMOS (UPDATABLE MODEL OUTPUT STATISTICS) CONNECTED TO

RDPS-300 DURING THE PARALLEL RUN COMPARED TO UMOS CONNECTED TO THE

OPERATIONAL SYSTEM SHOW COMPARABLE RESULTS FOR THE 00, 06, 12 AND 18 UTC

RUNS. SCORES DONE ON HISTORICAL CASES FOR WINTER 2011 AND 2012 SHOW

SIMILAR RESULTS EXCEPT FOR SOME STATIONS. MORE TRAINING WILL BE

PERFORMED DURING THE COMING WINTER SEASON TO KEEP THE UMOS PERFORMANCE AT

LEVEL WITH THE OPERATIONAL UMOS SYSTEM.

3.3.2 SCRIBE

THE SCRIBE FORECAST SYSTEM CONNECTED TO RDPS-300 IN PARALLEL MODE

PERFORMED SIMILARLY TO THE OPERATIONAL SYSTEM, WITH A SLIGHT IMPROVEMENT

IN FAVOUR OF THE NEW SYSTEM FOR THE PROBABILITY OF PRECIPITATION.

3.3.3 REGIONAL DETERMINISTIC WAVE PREDICTION SYSTEM (RDWPS)

THE SIGNIFICANT WAVE HEIGHT FORECAST IS IMPROVED WHEN CONNECTED TO THE

RDPS-300 OVER THE NORTH ATLANTIC DOMAIN. OVER THE GULF ST.LAWRENCE AND

THE GREAT LAKES DOMAINS THE SIGNAL IS NEUTRAL.

3.3.4 REGIONAL COUPLED SYSTEM - GOLF OF ST.LAWRENCE (RDPS-CGSL)

THIS SYSTEM WAS ALSO BROUGHT TO A SPATIAL RESOLUTION OF 10 KM. THE

EVALUATION OF FINAL FORECAST SERIES IN DEVELOPMENT SHOWED A SLIGHT

IMPROVEMENT FOR THE 2M AIR TEMPERATURE.

3.3.5 OTHER SYSTEMS

THE REGIONAL AIR QUALITY DETERMINISTIC PREDICTION SYSTEM (RAQDPS), THE

HIGH RESOLUTION (2.5KM) DETERMINISTIC PREDICTION SYSTEM (HRDPS), AND THE

REGIONAL DETERMINISTIC PRECIPITATION ANALYSIS (RDPA) HAVE ALL BEEN

ADAPTED TO THE NEW RDPS-300. THEIR PERFORMANCE AND CHANGES TO THESE

SYSTEMS ARE DOCUMENTED IN SEPARATE GENOT BULLETINS AND TECHNICAL NOTES

WHICH ARE ALSO AVAILABLE VIA THE LINK FOUND AT THE END OF THIS MESSAGE.

4.AVAILABILITY OF PRODUCTS

NO NEW ANALYSIS OR FORECAST PRODUCTS ACCOMPANY THIS UPGRADE OF THE

RDPS. THE INCREASE IN RESOLUTION AND THE NEW 4D-VAR ASSIMILATION

SYSTEM ARE MORE DEMANDING IN COMPUTER RESOURCES, SO TO ENSURE THE

AVAILABILITY OF MOST PRODUCTS AT THE SAME TIME THAN WITH THE SYSTEM

BEING REPLACED, THE DATA ACQUISITION CUT-OFF TIME HAS BEEN

SHORTENED TEMPORARILY BY 10 MINUTES TO 1 HOUR 55 MINUTES. ONGOING

CODE OPTIMIZATION COMBINED WITH PROGRAMMED INCREASES IN COMPUTING

CAPACITY WILL EVENTUALLY ALLOW US TO GO BACK TO THE PREVIOUS CUT-

OFF TIME. THE AVAILABILITY OF THE SCRIBE SYSTEM OUTPUT DESTINED TO

THE MSC REGIONAL PREDICTION CENTRES WILL NOT BE DELAYED EITHER.

Looks better although I don't see anything quantatative. There should be less bogus TCs.