547
FXUS10 KWNH 050503
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1203 AM EST SUN JAN 05 2020
VALID JAN 05/0000 UTC THRU JAN 08/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..SHORTWAVE TROUGH/LOW IMPACTING THE PACIFIC NORTHWEST
..ENERGY EJECTING OUT ACROSS THE PLAINS/MIDWEST THRU SUN
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-UKMET BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS ARE IN GOOD AGREEMENT WITH THE SHORTWAVE TRACKING
TOWARD THE GREAT LAKES REGION BY SUNDAY NIGHT, AND CLIPPING THE
NORTHEAST ON MONDAY. THE 12Z UKMET BECOMES A BIT SLOWER AND DEEPER
THAN THE REMAINING SUITE OF GUIDANCE AS IT EDGES TOWARD NORTHERN
NEW ENGLAND BY MONDAY. WILL SUGGEST A NON-UKMET BLEND AT THIS
POINT.
..SPLIT-FLOW TROUGH NEAR THE PACIFIC NORTHWEST BY SUN
..ENERGY REACHING THE GREAT LAKES/NORTHEAST TUES/WED
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z GFS/12Z ECMWF/12Z ECENS/18Z GEFS BLEND
CONFIDENCE: AVERAGE
THE MODELS ARE IN GOOD AGREEMENT WITH THE MID-LEVEL TROUGH AXIS
REACHING THE PACIFIC NORTHWEST ON SUNDAY. THIS ENERGY WILL RAPIDLY
ADVANCE DOWNSTREAM WITH A WEAK LOW CENTER CLIPPING THE NORTHERN
PLAINS AND REACHING THE GREAT LAKES BY
TUESDAY. THERE WILL BE SOME GRADUALLY AMPLIFICATION OF THE SYSTEM
AS IT CROSSES THE GREAT LAKES AND MORE SO AS IT APPROACHES THE
NORTHEAST. THE 12Z UKMET/CMC SOLUTIONS APPEAR A BIT TOO SLOW IN
TIME WITH THE SYSTEM. THE UKMET IS ALSO PERHAPS A LITTLE FARTHER
NORTH WITH ITS UPPER TROUGH/SURFACE LOW EVOLUTION. AS THE SYSTEM
APPROACHES THE NORTHEAST BY WEDNESDAY, THE 00Z NAM BECOMES A BIT
OF A DEEPER OUTLIER, WITH THE 12Z CMC ALSO ON THE DEEP SIDE OF THE
GUIDANCE. THE 00Z GFS AND 12Z ECMWF ARE CLOSEST TO THE MODEL
CONSENSUS AND HAVE REASONABLY GOOD AGREEMENT FROM THE LATEST
GEFS/ECENS MEANS, AND SO A BLEND OF THESE SOLUTIONS WILL BE
PREFERRED.
..SOUTHERN STREAM TROUGH/LOW NEAR THE TN VALLEY BY TUES
..SURFACE LOW IMPACTING THE MID-ATLANTIC/NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z NAM/GFS AND 12Z ECMWF
CONFIDENCE: AVERAGE
THE MODELS TAKE A SHORTWAVE TROUGH IN THE SOUTHERN STREAM AND
ADVANCE IT ACROSS THE LOWER MS AND TN VALLEYS THROUGH MONDAY AND
TUESDAY ALONG WITH A WAVE OF LOW PRESSURE. THIS SYSTEM WILL THEN
CROSS THE MID-ATLANTIC BY LATE TUESDAY AND DEEPEN OFFSHORE
SOUTHERN NEW ENGLAND BY EARLY WEDNESDAY. THE 12Z CMC IS A DEEPER
AND SLOWER OUTLIER WITH THIS SYSTEM, AND GRADUALLY THE 12Z UKMET
APPEARS TOO PROGRESSIVE. THE BETTER MODEL CLUSTERING AND ENSEMBLE
AGREEMENT RESIDES WITH THE 00Z NAM/GFS AND 12Z ECMWF, SO A BLEND
OF THESE SOLUTIONS WILL BE PREFERRED.
..SHORTWAVE/FRONTS APPROACHING THE PACIFIC NORTHWEST MON
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z NAM/GFS AND 12Z ECMWF
CONFIDENCE: AVERAGE
YET ANOTHER IN A SERIES OF SHORTWAVE TROUGHS WILL ARRIVE ACROSS
THE PACIFIC NORTHWEST LATE MONDAY INTO TUESDAY. INITIALLY A WARM
FRONT WILL CROSS THE REGION AHEAD OF THIS ENERGY, AND THE GUIDANCE
HANDLES THAT RELATIVELY WELL, BUT THE 12Z CMC IS A TAD SLOWER
THAN THE MODEL CONSENSUS WITH THIS FEATURE. THEN AS THE MAIN
SHORTWAVE AND ASSOCIATED COLD FRONT ARRIVES ON TUESDAY, THE MODELS
ARE IN GOOD AGREEMENT WITH EXCEPTION TO THE 12Z UKMET WHICH IS A
TAD OUT OF PHASE WITH THE OTHER GUIDANCE. WILL PREFER A BLEND OF
THE 00Z NAM/GFS AND 12Z ECMWF FOR NOW WHICH COLLECTIVELY SHOW GOOD
CLUSTERING.
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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