750
FXUS10 KWNH 020430
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1129 PM EST SAT FEB 01 2020
VALID FEB 02/0000 UTC THRU FEB 05/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH LATEST PREFERENCES AND CONFIDENCE
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..TROUGH EVOLUTION OVER THE EASTERN U.S. THROUGH SUNDAY
..DEEPENING COASTAL LOW TRACKING NORTH OFFSHORE OF NEW ENGLAND
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PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS ARE IN GOOD AGREEMENT WITH THE DETAILS OF THE
PROGRESSIVE TROUGH MOVING THROUGH THE EASTERN U.S. THROUGH THE
REMAINDER OF THE WEEKEND. AS THE TROUGH BECOMES NEGATIVELY TILTED
OFF THE COAST, A SURFACE LOW PRESSURE WILL DEEPEN AND LIFT
NORTHEAST WELL OFFSHORE, EVENTUALLY IMPACTING PORTIONS OF
SOUTHEAST CANADA, ESPECIALLY THE MARITIME ON SUNDAY. A GENERAL
MODEL BLEND IS BE PREFERRED.
..DEEP LONGWAVE TROUGH EVOLVING OVER THE WESTERN U.S.
..SURFACE WAVE ACTIVITY DEVELOPING OVER THE LOWER/MID MS VALLEY
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PREFERENCE: BLEND OF 12Z CMC/ECMWF AND 12Z GEFS/ECENS MEANS
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
THE 00Z NAM/GFS AGAIN JUST AS IT IN PREVIOUS RUNS CONTINUES TO BE
TOO PROGRESSIVE WITH THE EVOLUTION OF THE DEEP LONGWAVE TROUGH
EVOLUTION OVER THE WESTERN U.S. OVER THE NEXT FEW DAYS.
INTERESTINGLY ENOUGH, THE QUICK PROGRESSION OF THE LONGWAVE
TROUGH, AS SHOWN BY THE NAM/GFS, ALLOWS PHASING TO OCCUR WITH
NORTHERN STREAM TROUGH RESULTING IN COOLER THERMALS AND ALSO A
SHARPER NORTHERN AXIS TO THE QPF. CONVERSELY, THE 12Z UKMET
APPEARS TOO SLOW WITH THE TROUGH PROGRESSION TOWARD THE HIGH
PLAINS BY THE END OF THE PERIOD. THE REMAINING GUIDANCE LED BY THE
12Z CMC/ECMWF, AND ALSO THE LATEST GEFS/ECENS MEANS SHOW GENERALLY
GOOD AGREEMENT WITH THE TROUGH TIMING/DEPTH AND SURFACE WAVE
ACTIVITY. A BLEND OF THE NON-GFS/UKMET/NAM IS PREFERRED.
..NORTHERN STREAM TROUGH CLIPPING THE NORTHERN PLAINS TUESDAY
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PREFERENCE: BLEND OF THE 12Z CMC/ECMWF AND 12Z ECENS
CONFIDENCE: ABOVE AVERAGE
THERE ARE SUBTLE DIFFERENCES WITH RESPECT TO A NORTHERN STREAM
TROUGH CLIPPING THE NORTHERN PLAINS INTO THE GREAT LAKES REGION BY
EARLY WEDNESDAY. THE 12Z UKMET IS TOO PROGRESSIVE WHILE THE 00Z
GFS/NAM ARE TOO AMPLIFIED AND A TAD SLOWER ALLOWING THIS PIECE OF
ENERGY TO PHASE WITH THE LONGWAVE TROUGH TO THE SOUTH AND WEST.
THIS RESULTS IN DIFFERENCES IN THE THERMALS AND QPF, ESPECIALLY
TUESDAY INTO WEDNESDAY. IT APPEARS, BASED ON CONTINUITY AND THE
OVERALL SPEED OF THIS TROUGH, THAT A FLATTER TROUGH AXIS ADVANCING
EAST WOULD SEEM MOST REASONABLE. THEREFORE, A BLEND OF THE 12Z
CMC/EC AND ECENS IS 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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