Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
317 AM EDT Wed Aug 12 2020
Valid Aug 12/0000 UTC thru Aug 15/1200 UTC
...See NOUS42 KWNO (ADMSDM) for the status of the upper air
ingest...
00Z Model Evaluation Including Preferences and Forecast Confidence
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Longwave trough over the Northwest to the Northern Plains through
Friday
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Preference: NAM/CMC/ECMWF blend
Confidence: Slightly above average
A broad upper level trough, in conjunction with a closed low over
southwestern Canada, will be in place across the northwestern U.S.
through the middle of the week, and then should be in place across
the northern Plains by the weekend. This will sustain a cold
front tracking from the northern Rockies to the Dakotas. The 00Z
GFS becomes faster and more amplified with this trough by 12Z
Friday across the Dakotas, and the 12Z UKMET trends stronger by
Friday night across the Upper Midwest.
Northeastern U.S. upper trough
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Preference: ECMWF/CMC blend
Confidence: Average
An upper level trough axis gradually builds in across New England
and eastern Canada by the end of the week, downstream of a
building ridge axis across Ontario and western Quebec. The 00Z
NAM is strongest with the trough, and the GFS is slightly east of
the model consensus. Blending the ECMWF and CMC would yield a
suitable starting point in the process process.
Southeastern U.S. upper trough
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Preference: General model compromise
Confidence: Slightly Above Average
A weak closed low currently over Missouri will slowly track
eastward and evolve into an open trough as it reaches the Ohio
Valley and southern Appalachians by this weekend. A general model
compromise would work well here.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
This product will terminate August 15, 2020:
www.weather.gov/media/notification/pdf2/scn20-58pmdhmd_termination.
pdf
Hamrick