967
FXUS10 KWNH 030647
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
145 AM EST FRI JAN 03 2020
VALID JAN 03/0000 UTC THRU JAN 06/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH LATEST PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..AMPLIFYING LONGWAVE TROUGH ACROSS THE CENTRAL U.S.
..SURFACE LOW FROM THE LOWER MS VALLEY TO THE NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z GFS/ECMWF/CMC/GEFS AND 12Z ECENS MEAN BLEND
CONFIDENCE: AVERAGE
A SPLIT FLOW UPPER TROUGH WILL EJECT OUT ACROSS THE PLAINS GOING
THROUGH THE END OF THE WEEK, WITH INITIALLY THE DOMINANT
AMPLIFICATION OCCURRING DOWN OVER THE SOUTHERN HIGH PLAINS.
HOWEVER, BY LATE FRIDAY, MULTIPLE PIECES OF ENERGY IN THE NORTHERN
STREAM WILL DIG DOWN ACROSS THE MIDWEST AND LEAD TO A MORE
DOMINANT NORTHERN STREAM TROUGH AND CLOSED LOW EVOLUTION WHICH
WILL INTERACT WITH THE SOUTHERN STREAM ENERGY. THIS WILL LEAD TO
SURFACE LOW DEVELOPMENT OVER THE LOWER MS VALLEY WHICH WILL LIFT
NORTHEAST TOWARD THE OH VALLEY BY SATURDAY. THIS SYSTEM WILL CROSS
THE NORTHERN MID-ATLANTIC BY SATURDAY EVENING WITH LOW PRESSURE
REDEVELOPING SOUTH OF LONG ISLAND BY EARLY SUNDAY. THE MODELS HAVE
OVERALL TRENDED WEAKER COMPARED TO LAST NIGHT, AND DO NOT SUGGEST
AS PHASED OF A SYSTEM IMPACTING NEW ENGLAND. THE 00Z NAM OVERALL
BECOMES A BIT MORE PROGRESSIVE WITH THE SYSTEM COMPARED TO THE
GLOBAL MODELS. THE 00Z GFS, 00Z CMC AND 00Z ECWMF ARE RATHER WELL
CLUSTERED NOW AND CLOSE TO THE 00Z GEFS/12Z ECENS MEANS, ALTHOUGH
THE 00Z ECMWF DID TEND TO SHIFT ITS LOW TRACK A LITTLE FARTHER
NORTH AS IT CROSSES SOUTHERN NEW ENGLAND ON SATURDAY. THE 00Z
UKMET IS ALSO VERY CLOSE TO THE MODEL CONSENSUS NOW, ALTHOUGH AS
THE LOW PULLS AWAY FROM NEW ENGLAND, THE UKMET STARTS TO EDGE
TOWARD THE FASTER SIDE OF THE GUIDANCE. WILL RECOMMEND A
MULTI-MODEL BLEND OF THE GFS/ECMWF/CMC AND THE LATEST GEFS/ECENS
MEANS.
..SHORTWAVE TROUGH/LOW IMPACTING THE PACIFIC NORTHWEST
..ENERGY EJECTING OUT ACROSS THE PLAINS/MIDWEST BY SAT/SUN
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS ARE IN GOOD AGREEMENT WITH THE DETAILS OF FAST UPSTREAM
PACIFIC FLOW AIMING TOWARD THE PACIFIC NORTHWEST WHICH WILL DRIVE
ANOTHER SHORTWAVE AND STRONG SURFACE LOW EASTWARD TO NEAR THE
NORTHERN END OF VANCOUVER ISLAND BY FRIDAY NIGHT. A COLD FRONT
ASSOCIATED WITH THIS WILL THEN CROSS THE PACIFIC NORTHWEST BY
EARLY SATURDAY. THIS SYSTEM WILL ADVANCE VERY QUICKLY DOWNSTREAM
ACROSS THE INTERMOUNTAIN WEST AND ACROSS THE NORTHERN PLAINS AND
MIDWEST SATURDAY AND SUNDAY BEFORE IMPACTING THE GREAT LAKES ON
MONDAY. THE 00Z CMC HAS COME IN MUCH CLOSER TO THE OTHERWISE WELL
CLUSTERED MODEL SUITE, AND SO A GENERAL MODEL BLEND WILL BE
PREFERRED.
..SPLIT FLOW TROUGH NEAR THE PACIFIC NORTHWEST BY SUN
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
THE MODELS SHOW A NEW SPLIT FLOW UPPER TROUGH AND ATTENDANT FRONT
APPROACHING THE PACIFIC NORTHWEST BY SUNDAY. THE 00Z NAM/GFS
SOLUTIONS ARE A TAD FASTER THAN THE 00Z CMC/UKMET/ECMWF SOLUTIONS
WITH THE SYSTEM. HOWEVER, COLLECTIVELY ALL OF THE SOLUTIONS ARE
QUITE PROGRESSIVE WITH THE LARGE SCALE FLOW. SOME THE ENERGY WITH
THIS WILL SPILL OUT ACROSS THE NORTHERN HIGH PLAINS BY EARLY
MONDAY WITH A WEAK LEESIDE LOW DEVELOPING EAST OF THE ROCKIES.
GIVEN THE MODEST MASS FIELD SPREAD WITH THIS SYSTEM, A GENERAL
MODEL BLEND WILL BE PREFERRED.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
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