173
FXUS10 KWNH 010437
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1236 AM EDT WED JUL 01 2020
VALID JUL 01/0000 UTC THRU JUL 04/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CLOSED LOW/TROUGH EXITING NEW ENGLAND BY THURSDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-CMC BLEND
CONFIDENCE: ABOVE AVERAGE
MODEL GUIDANCE IS IN EXCELLENT AGREEMENT GRADUALLY TAKING THE
UPPER LOW AND ASSOCIATED TROUGH AXIS OVER NEW ENGLAND GRADUALLY
OFF TO THE EAST-SOUTHEAST OVER THE NEXT COUPLE OF DAYS AND
ULTIMATELY OFFSHORE THE EAST COAST. THE 12Z CMC WAS SEEN AS BEING
A BIT MORE PROGRESSIVE IN TIME AS THE ENERGY MOVES OUT TO SEA. THE
REMAINING GUIDANCE IS WELL CLUSTERED SO A NON-CMC BLEND WILL BE
PREFERRED.
DEEP UPPER TROUGH/CLOSED LOW ACROSS THE INTERMOUNTAIN WEST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/12Z UKMET/12Z ECMWF
CONFIDENCE: AVERAGE
THE UPPER LOW/TROUGH IMPACTING THE NORTHERN INTERMOUNTAIN REGION
WILL ADVANCE NORTH INTO SOUTHWEST CANADA ON WEDNESDAY AS ANOTHER
SHORTWAVE TROUGH DROPS SOUTHWARD OVER THE PACIFIC NORTHWEST. THE
PHASING OF THIS ENERGY WILL KEEP THE CLOSED LOW IN PLACE OVER
SOUTHWEST CANADA MUCH OF THE PERIOD. HOWEVER, ANOTHER COMPACT
CLOSED LOW AND ASSOCIATED TROUGH IS FORECAST TO DROP SOUTH DOWN
THE COAST OF BRITISH COLUMBIA AND INTO THE PACIFIC NORTHWEST GOING
THROUGH THURSDAY. THE MODELS GENERALLY SUPPORT TWO CLOSED LOWS
THEN BY FRIDAY WITH ONE NEAR THE PACIFIC NORTHWEST AND ONE FARTHER
NORTH OVER PARTS OF ALBERTA. THE 00Z NAM BY FRIDAY TENDS TO BE A
BIT STRONGER WITH THE BROADER HEIGHT FALL EVOLUTION. THE 12Z CMC
IS MOST OUT OF PHASE COMPARED TO THE OTHER MODELS AS IT LIFTS MORE
ENERGY FARTHER NORTH THROUGH SOUTHWEST CANADA AND DOES NOT HAVE AS
STRONG OF A TROUGH IMPACTING THE PACIFIC NORTHWEST BY THE END OF
THE PERIOD. THERE ARE SOME MODEST SPATIAL/DEPTH DIFFERENCES WITH
THE 00Z GFS, 12Z UKMET AND 12Z ECMWF, BUT THESE SOLUTIONS CLUSTER
TOGETHER BETTER OVERALL, AND SO A BLEND OF THESE SOLUTIONS WILL BE
PREFERRED.
MCV CROSSING THE MIDWEST THROUGH WEDNESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
A CONVECTIVELY ENHANCED MCV SITUATED ALONG THE IA/IL BORDER, STUCK
IN BETWEEN A DEEP LAYER RIDGE TO ITS SOUTH AND TO ITS NORTH IS
FORECAST TO GRADUALLY DAMPEN AND SHEAR OUT OVER THE NEXT COUPLE OF
DAYS WITH SOME OF THE REMNANT ENERGY DIGGING SOUTHEASTWARD AS THE
RIDGE OVER THE GULF COAST STATES BREAKS DOWN AND ALLOWS A BROADER
TROUGH TO ENVELOPE MUCH OF THE DEEP SOUTH AND INTERIOR OF THE
SOUTHEAST. THE LATEST GUIDANCE GENERALLY AGREES WITH THIS
SCENARIO, SO A GENERAL MODEL BLEND WILL AGAIN BE PREFERRED WITH
THIS ENERGY.
MID-LEVEL CLOSED LOW OVER THE GULF COAST BY FRIDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-UKMET BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
MID-LEVEL TROUGHING AND A DEVELOPING CLOSED LOW OVER THE GULF
COAST STATES IS EXPECTED BY THE END OF THE WEEK, WITH WEAK
SHORTWAVE ENERGY DROPPING DOWN FROM THE MID-SOUTH. THERE IS DECENT
AGREEMENT WITH THE LARGER SCALE MASS FIELD EVOLUTION AMONG THE
MODELS, BUT THE 12Z UKMET BY THE END OF THE PERIOD IS NOTABLY
WEAKER WITH ITS TROUGHING/CLOSED LOW. THE 00Z GFS ALSO MAY BE A
TAD ON THE STRONG SIDE, BUT THERE IS SOME ENSEMBLE SUPPORT FOR
THIS FROM THE LATEST GEFS MEAN, SO FOR NOW A NON-UKMET BLEND WILL
BE PREFERRED.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
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