Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1107 PM EST Fri Feb 28 2020
Valid Feb 29/0000 UTC thru Mar 03/1200 UTC
...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...
00z NAM/GFS Evaluation with Preferences & Forecast Confidence
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NAM/GFS initialization errors do not seem to degrade their short
range forecasts.
System slowly pulling away from the Northeast through Sunday
System moving through southern Canada & trailing front Sat/Sun
System dropping down toward US/Canadian border Mon/Tue
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The guidance shows good agreement with these features. A
compromise of the 12z UKMET, 12z Canadian, 00z NAM, 00z GFS, and
12z ECMWF is preferred with above average confidence.
System dropping down the West Coast Sunday & Monday
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Preference: Non-GFS compromise
Confidence: Slightly above average
Starting on late Sunday, the 00z GFS is more eastward aloft than
the other guidance, which appears to be due to a slightly weaker
northern stream ridge moving over the top of the system. The
guidance has been stable showing a system moving near and offshore
the CA coast since last night, which fits conceptual models
considering the building ridging to its north forcing the mid- to
upper-low southward and a lack of an upstream kicker shortwave. A
compromise of the 00z NAM, 12z UKMET, 12z Canadian, and 12z ECMWF
is advised with slightly above average confidence.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Roth