707
FXUS10 KWNH 030640
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
139 AM EST TUE DEC 03 2019
VALID DEC 03/0000 UTC THRU DEC 06/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..DEEP CLOSED LOW IMPACTING NEW ENGLAND
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
DIFFERENCES WITH THE DEEP LAYER CYCLONE STILL IMPACTING NEW
ENGLAND ARE SUFFICIENTLY MINOR THAT A GENERAL MODEL BLEND CAN BE
PREFERRED AS THE SYSTEM PULLS AWAY ON TUESDAY.
..UPPER LOW OFFSHORE THE WEST COAST THROUGH TUESDAY
..ENERGY THEN CROSSING THE SOUTHERN TIER THROUGH THURSDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND...THROUGH 36 HOURS
00Z CMC/ECMWF BLEND...AFTER 36 HOURS
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
THERE IS RATHER GOOD AGREEMENT WITH THE EVOLUTION OF THE UPPER LOW
OFFSHORE THE WEST COAST THROUGH ABOUT 36 HOURS, BUT THEREAFTER THE
00Z GFS BECOMES A RELATIVELY PROGRESSIVE OUTLIER SOLUTION (COMMON
BIAS) AS THE ENERGY TRAVERSES THE SOUTHERN TIER OF THE NATION
GOING THROUGH WEDNESDAY AND THURSDAY. THE GFS IS ALSO A BIT DEEPER
WITH SURFACE LOW PRESSURE THAT EVOLVES ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY THROUGH THE PERIOD. THE 00Z NAM IS ALSO ON THE
STRONGER SIDE OF THE GUIDANCE AT LEAST ALOFT. ON THE FLIP SIDE,
THE 00Z UKMET IS SLOWER AND CURIOUSLY FLATTER BY COMPARISON. THE
00Z CMC AND 00Z ECMWF SPLIT THE DIFFERENCE IN BETWEEN SLOWER AND
FASTER CAMPS AND CLUSTER TOGETHER RATHER WELL. THE LATEST GEFS AND
ECENS CLUSTERS/MEANS OVERALL FAVOR THE CMC/ECMWF CAMP, AND SO A
BLEND OF THESE SOLUTIONS WILL BE PREFERRED AFTER 36 HOURS, WITH A
GENERAL MODEL BLEND PRIOR TO THIS.
..NEXT AMPLIFYING TROUGH ACROSS THE OH VALLEY/NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS AMPLIFY A SHORTWAVE TROUGH DOWN ACROSS THE OH VALLEY
AND NORTHEAST TUESDAY AND WEDNESDAY. THE 00Z UKMET AND 00Z CMC
HAVE COME IN A LITTLE WEAKER COMPARED TO THEIR PREVIOUS RUNS, AND
ARE IN VERY GOOD AGREEMENT WITH THE NAM/GFS AND ECMWF. SO, A
GENERAL MODEL BLEND WILL NOW BE PREFERRED WITH THIS ENERGY.
..WEAK SHORTWAVE/LOW CLIPPING THE NORTHERN PLAINS WEDNESDAY
..CROSSING THE GREAT LAKES ON THURSDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z GFS/CMC BLEND
CONFIDENCE: AVERAGE
THE MODELS SUPPORT A WEAK SHORTWAVE AND ASSOCIATED SURFACE
LOW/FRONT CLIPPING THE NORTHERN PLAINS LATE WEDNESDAY AND QUICKLY
REACHING THE GREAT LAKES REGION BY LATE THURSDAY. THE 00Z ECMWF
CAME IN A BIT SLOWER AND IS NOW THE SLOWEST SOLUTION WITH THIS
SYSTEM AND ESPECIALLY WITH ITS COLD FRONT EVOLUTION. THE 00Z UKMET
IS NOW THE MOST PROGRESSIVE AND WEAKEST SOLUTION. THE NAM/GFS AND
CMC NOW CLUSTER IN BETWEEN, ALTHOUGH THE NAM LATE IN THE PERIOD
HAS ITS SURFACE LOW A BIT NORTH OF THE REMAINING GUIDANCE. THE GFS
AND CMC NOW REPRESENT THE MODEL CONSENSUS AND HAVE GOOD ENSEMBLE
SUPPORT, SO A BLEND OF THESE SOLUTIONS WILL BE PREFERRED.
..DEEP CLOSED LOW OFFSHORE THE WEST COAST BY FRIDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-CMC BLEND...LED BY A 00Z GFS/ECMWF BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS SUPPORT ANOTHER VERY DEEP CLOSED LOW EVOLVING OFFSHORE
OF THE WEST COAST BY FRIDAY. THE 00Z CMC IS DISPLACED A BIT
NORTHEAST OF THE MODEL CONSENSUS WITH ITS UPPER-LEVEL AND SURFACE
LOW REFLECTIONS. THE MAJORITY CLUSTER OF SOLUTIONS SUGGEST A
SYSTEM THAT WILL BE A BIT SLOWER TO ADVANCE EAST AT THE END OF THE
PERIOD, WHICH IS STRONGLY SUGGEST BY THE GEFS AND ECENS CLUSTERS.
A NON-CMC BLEND WILL BE PREFERRED WITH STRONG WEIGHTING TOWARD A
00Z GFS/ECMWF BLEND.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
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