Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
124 AM EST Fri Feb 28 2020
Valid Feb 28/0000 UTC thru Mar 02/1200 UTC
...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...
00z Model 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
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The guidance shows good agreement here, so prefer a compromise of
the 12z Canadian, 12z UKMET, 12z ECMWF, 00z NAM, and 00z GFS with
above average confidence.
System moving through southern Canada & its trailing front
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Preference: Closest to the 00z ECMWF
Confidence: Slightly above average
The guidance shows spread with this system's progression, though
some pieces of guidance have trended quicker, with the 00z UKMET
the slowest aloft while the 00z GFS is the quickest/broadest
aloft. This system is moving through an increasingly zonal flow
pattern aloft, which along with the trend argues for a solution no
slower than the UKMET. The GFS can be speedy with systems in the
Westerlies, but that can't be ruled out in an increasingly zonal
flow pattern. The 00z ECMWF makes for a nice compromise solution
here and is preferred with slightly above average confidence.
System dropping down the West Coast Sunday & Monday
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Preference: UKMET/Canadian/ECMWF compromise
Confidence: Slightly above average
By Sunday, the 00z UKMET ends up more westward with this system
than the other guidance, but there has been a westward shift in
the UKMET/ECMWF guidance. As a northern stream ridge builds in
the wake of the system moving just north of the US/Canadian
border, a southward moving system near the West Coast makes sense.
A compromise of the 00z UKMET, 00z Canadian, and 00z ECMWF is
preferred 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