Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1222 AM EDT Mon Jul 23 2018

Valid Jul 23/0000 UTC thru Jul 26/1200 UTC

...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...

00Z NAM/GFS evaluation with preliminary model preferences
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Central US Preference: ECMWF/UKMET/GFS blend
Confidence:  No better than average 
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Near the Central US/Canadian border and Great Lakes, the 00z NAM
is its usual deep, southwesterly self with the main mid-level
closed low with no real support so it was not considered plausible
due to its known bias.  Otherwise, the 12z Canadian was a quick
outlier.  A compromise of the intermediate 12z ECMWF, 12z UKMET,
and 00z GFS was preferred both aloft and at the surface across the
Midwest/Plains with confidence no better than average.


Eastern US Preference: Non-UKMET compromise
Confidence: Above average
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The 12z UKMET was somewhat quicker with the upper trough/front
moving through the region Thursday morning.  Considering the
strength of anomalously far north ridge in the north Atlantic,
believe a slower progression makes more sense.  Preferred a
compromise of the 12z ECMWF, 12z Canadian, 00z GFS, and 00z NAM
with above average confidence here.


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Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml

Roth