Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
251 AM EDT Fri Aug 07 2020
Valid Aug 07/0000 UTC thru Aug 10/1200 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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Overall weather pattern across the continental U.S.
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Preference: General model blend
Confidence: Slightly above average
There is generally good synoptic scale model agreement across the
continental U.S. and into Canada through Monday morning. There
are some minor model differences in the placement and strength of
the closed mid level low tracking across Saskatchewan into
Manitoba this weekend, with the NAM a bit more amplified compared
to the model consensus and the GEFS mean slightly faster with the
progression of the main surface low across central Canada. Though
the differences are relatively minor, they do have ramifications
downstream, as short wave energy ejected from the base of the
closed mid level low tracks through the progressive mid level flow
across the northern Mid Atlantic and southern New England,
especially after Saturday afternoon. Though there is some spread
in the timing of the short waves, that would be expected in the
fast mid level flow. Overall, a general model blend should
suffice, allowing the timing differences to be muted to some
degree.
There is also some model spread with the development of a surface
wave on a front extending from the Upper Mississippi Valley into
the central High Plains after Saturday night. The spread may be
tied to the short wave timing in the fast mid level flow, but the
differences in the surface low placement appear to be typical for
a Day 2/Day 3 forecast, so a model blend should work here as well.
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