163
FXUS10 KWNH 071656
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1255 PM EDT MON OCT 07 2019
VALID OCT 07/1200 UTC THRU OCT 11/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION WITH PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..UPPER TROUGH CROSSING THE GREAT LAKES/NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS SHOW VERY GOOD AGREEMENT WITH THE DETAILS OF THE UPPER
TROUGH AND ASSOCIATED SHORTWAVE ENERGY CROSSING THE GREAT LAKES
AND NORTHERN NEW ENGLAND TODAY THROUGH TUESDAY. A GENERAL MODEL
BLEND WILL BE PREFERRED.
..ENERGY AMPLIFYING OVER CENTRAL APPALACHIANS/MID-ATLANTIC
..DEEPENING SURFACE LOW PRESSURE OFF THE EAST COAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z UKMET/06Z GEFS/00Z ECENS MEAN
CONFIDENCE: SLIGHTLY BELOW AVERAGE
THE GUIDANCE AGAIN SHOWS SHORTWAVE ENERGY ADVANCING ACROSS THE
MID-MS AND OH VALLEYS THAT WILL BREAK AWAY FROM THE WESTERLIES AND
AMPLIFY TOWARD THE CENTRAL APPALACHIANS THROUGH TUESDAY, WITH AT
LEAST A WEAK MID-LEVEL CLOSED LOW EVOLVING NEAR THE NORTHERN
MID-ATLANTIC REGION BY WEDNESDAY. ON THURSDAY, THE MODELS SUPPORT
THE CLOSED LOW FEATURE BEING GENERALLY SOUTHEAST OF LONG ISLAND.
THE 12Z NAM/00Z UKMET AND 00Z ECMWF ARE THE STRONGEST SOLUTIONS,
FOLLOWED BY THE MODESTLY WEAKER 12Z GFS AND 00Z ECMWF. THIS ENERGY
IS EXPECTED TO INTERACT WITH AN AREA OF DISTURBED WEATHER
NORTHEAST OF THE BAHAMAS THAT WILL BE LIFTING NORTHWEST TO
OFFSHORE OF THE CAROLINAS ON TUESDAY. THE GUIDANCE IS IN VERY GOOD
AGREEMENT IN DEPICTING OFFSHORE CYCLOGENESIS AS THE UPSTREAM
HEIGHT FALLS APPROACH THE EAST COAST. THERE REMAINS A FAIR AMOUNT
OF LATITUDINAL SPREAD IN THE GUIDANCE WITH WHERE THIS SECONDARY
CYCLOGENESIS WILL FOCUS, AS THE 12Z NAM/00Z CMC SOLUTIONS ARE
CLUSTERED FARTHER NORTH, AND THE 00Z ECMWF FARTHER SOUTH. THE 12Z
GFS AND 00Z UKMET ARE OVERALL SPLITTING THE DIFFERENCE BETWEEN
CAMPS. THE 06Z GEFS MEAN FAVORS THE GFS SOLUTION, WITH THE 00Z
ECENS MEAN SIDING WITH THE ECMWF, WHICH SUGGESTS THE NAM/CMC
SOLUTIONS ARE LIKELY A TAD TOO FAR NORTH THROUGH THE PERIOD. A
COMPROMISE BETWEEN THE ENSEMBLE MEANS WILL BE PREFERRED, ALONG
WITH THE UKMET WHICH COLLECTIVELY APPEAR TO APPROXIMATE THE MODEL
CONSENSUS WITH THIS SYSTEM. CONFIDENCE REMAINS RATHER LIMITED
GIVEN THE LEVEL OF ENSEMBLE AND DETERMINISTIC MODEL SPREAD WITH
THIS SYSTEM.
..WEAK SURFACE LOW PRESSURE IMPACTING THE FL PENINSULA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
MEANWHILE, A SEPARATE AREA OF DISTURBED WEATHER ASSOCIATED WITH A
TROPICAL WAVE/SURFACE AND WEAK AREA OF LOW PRESSURE WILL BE
ADVANCING WEST ACROSS SOUTH FLORIDA TODAY AND TONIGHT WHICH WILL
ADVANCE INTO THE EASTERN GULF OF MEXICO ON TUESDAY BEFORE
WEAKENING AND LOSING ITS IDENTITY. A GENERAL MODEL BLEND CAN BE
PREFERRED WITH THIS SYSTEM.
..DEEP UPPER TROUGH/CLOSED LOW AMPLIFYING OVER THE WEST
..HIGH PLAINS CYCLOGENESIS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 12Z GFS/00Z UKMET AND 00Z ECMWF
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
THE MODELS ARE IN VERY GOOD AGREEMENT ON AMPLIFYING A NORTHERN
STREAM TROUGH DOWN TOWARD THE PACIFIC NORTHWEST, NORTHERN ROCKIES
AND NORTHERN HIGH PLAINS LATER TODAY AND WHICH WILL SEND A VERY
STRONG COLD FRONT SOUTHEAST FROM CANADA ALONG WITH MUCH COLDER
AIR. AS THE COLD FRONT ADVANCES SOUTHEAST, ONE WAVE OF LOW
PRESSURE WILL DEVELOP ALONG IT OVER SOUTHEAST MT BY LATE TUESDAY
WHICH WILL CROSS THE DAKOTAS THROUGH EARLY WEDNESDAY BEFORE THEN
DAMPENING OUT. THE MODELS SHOW EXCELLENT AGREEMENT WITH THIS
EVOLUTION. THEN AS THE COLD FRONT ADVANCES DOWN THE FRONT RANGE OF
THE ROCKIES BY LATE WEDNESDAY, A NEW AREA OF STRONG CYCLOGENESIS
IS EXPECTED TO TAKE PLACE OVER EASTERN CO WHICH WILL THEN ADVANCE
EAST AND ELONGATE ALONG THE FRONT ON THURSDAY AS IT CROSSES THE
CENTRAL PLAINS. THE 12Z NAM GRADUALLY BECOMES A BIT STRONGER THAN
THE GLOBAL MODELS WITH ITS DEPTH OF THE TROUGH AND CLOSED LOW OVER
THE INTERMOUNTAIN WEST BY LATE WEDNESDAY AND THURSDAY. THE 00Z CMC
BY THE END OF THE PERIOD APPEARS TO BE PLACING THE CORE OF ITS
HEIGHT FALLS A BIT TOO FAR NORTH OVER THE NORTHERN HIGH PLAINS AS
THE GUIDANCE SUITE SUPPORTS A CONSOLIDATION OF MID-LEVEL ENERGY
FARTHER SOUTH CLOSER TO THE CENTRAL ROCKIES. THE CMC AS A RESULT
ENDS UP BEING A BIT MORE PROGRESSIVE WITH ITS COLD FRONT LATE IN
THE PERIOD AND MORE OUT OF PHASE COMPARED TO THE OTHER MODELS. THE
BETTER MODEL CLUSTERING AND ENSEMBLE SUPPORT AT THIS POINT FAVORS
A BLEND OF THE 12Z GFS/00Z UKMET AND 00Z ECMWF, AND SO A BLEND OF
THESE SOLUTIONS WILL BE PREFERRED.
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
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