786
FXUS10 KWNH 040430
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1129 PM EST TUE DEC 03 2019
VALID DEC 04/0000 UTC THRU DEC 07/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..UPPER LOW ARRIVING CALIFORNIA ON WEDNESDAY
..ENERGY THEN CROSSING THE SOUTHERN U.S. THROUGH FRIDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND...THROUGH 48 HOURS
NON-UKMET BLEND...AFTER 48 HOURS
CONFIDENCE: ABOVE AVERAGE
THERE IS RATHER GOOD AGREEMENT WITH THE EVOLUTION OF THE UPPER LOW
OFFSHORE THE WEST COAST AND ITS ASSOCIATED SURFACE REFLECTION
GOING THROUGH ABOUT 48 HOURS, AS THE MODELS TAKE THIS SYSTEM
INLAND ACROSS CENTRAL/SOUTHERN CA ON WEDNESDAY, AND THEN
PROGRESSIVELY EAST ACROSS THE FOUR CORNERS AND SOUTHERN PLAINS
THROUGH THURSDAY. THE SYSTEM WILL BE GRADUALLY WEAKENING WITH
TIME, AND ESPECIALLY AS IT CROSSES FROM THE SOUTHERN PLAINS TO THE
SOUTHEAST BY THE END OF THE WEEK. THE 12Z UKMET AFTER 48 HOURS
BECOMES A BIT OF A WEAKER AND SOMEWHAT SLOWER OUTLIER SOLUTION.
THE REMAINING GUIDANCE IS CLUSTERED WELL ENOUGH THAT A NON-UKMET
BLEND CAN BE PREFERRED AFTER 48 HOURS. A GENERAL MODEL BLEND
APPEARS FINE PRIOR TO THIS.
..AMPLIFYING TROUGH ACROSS THE NORTHEAST THROUGH WEDNESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/12Z ECMWF AND 12Z UKMET
CONFIDENCE: ABOVE AVERAGE
THE MODELS AMPLIFY A SHORTWAVE TROUGH INTO THE NORTHEAST U.S.
THROUGH WEDNESDAY. THE 00Z NAM IS A TAD STRONGER THAN THE GLOBAL
MODELS WITH THIS SYSTEM. ALTHOUGH, OF THE GLOBAL MODELS, THE 12Z
CMC APPEARS TO BE A LITTLE TOO WEAK. THE ENSEMBLE MEAN CLUSTERS
PER THE GEFS AND ECENS, AND THE LATEST HREF CLUSTER, FAVOR A
SOLUTION TOWARD THE 00Z GFS/12Z ECMWF, AND 12Z UKMET AT THIS TIME.
..WEAK SHORTWAVE/LOW CLIPPING THE NORTHERN PLAINS WEDNESDAY
..CROSSING THE GREAT LAKES/NORTHEAST THROUGH THURSDAY/FRIDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/12Z ECMWF AND 12Z UKMET
CONFIDENCE: ABOVE 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 BEFORE ARRIVING
ACROSS THE NORTHEAST ON FRIDAY. THE 00Z NAM AND 12Z CMC BOTH END
UP BEING SOMEWHAT STRONGER OUTLIERS WITH THIS SYSTEM AS IT CROSSES
THE GREAT LAKES AND NORTHEAST. THERE IS BETTER ENSEMBLE SUPPORT
FOR THE MODESTLY WEAKER 00Z GFS/12Z ECMWF AND 12Z UKMET SOLUTIONS,
ALONG WITH THE 00Z ARW/NMMB HIRES MODEL SOLUTIONS (AT LEAST
THROUGH 48 HOURS).
..DEEP CLOSED LOW OFFSHORE THE WEST COAST BY FRIDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-GFS BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS SUPPORT ANOTHER VERY DEEP CLOSED LOW EVOLVING OFFSHORE
OF THE WEST COAST BY FRIDAY. THE 00Z GFS EDGES THE CLOSED LOW A
BIT CLOSER TO THE COAST VERSUS THE REMAINING SUITE OF GUIDANCE.
THERE IS SOME SUPPORT FROM THE LATEST GEFS CLUSTER FOR THIS
SLIGHTLY MORE PROGRESSIVE GFS SOLUTION, BUT THE MAJORITY CLUSTER
OF GUIDANCE IS A LITTLE SLOWER AND FARTHER OFFSHORE AT THE END OF
THE PERIOD, SO A NON-GFS BLEND WILL BE PREFERRED WITH THIS SYSTEM.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page