Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1139 AM EST Mon Nov 25 2019
Valid Nov 25/1200 UTC thru Nov 29/0000 UTC
...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...
12Z Model Evaluation with Preferences and Forecast Confidence
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...Overall Pattern Across the CONUS...
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Preference: Non-CMC model blend
Confidence: Slightly above average
Models have come into better alignment with the synoptic pattern
and major features over the next few days. The most significant
spread appears to be related to the amplitude and strength of two
troughs: (1) a negatively tilted trough ejecting from the Plains
into the Great Lakes, and (2) a rapidly amplifying trough pushing
into the West Coast.
With the exception of the 00Z CMC (less amplified and shifted
slightly north) with the West Coast trough, there does not appear
to be a systematic bias to warrant the exclusion of a particular
model from the preference. The model QPF is also fairly similar at
larger scales, and therefore a non-CMC general blend is the
preference.
In terms of notable trends, there has been a slight northwest
shift with the low track associated with the central U.S. storm.
The 12Z NAM is situated furthest west, but the 00Z ECMWF ensemble
mean is also west of the 00Z deterministic run. Therefore, it is
possible other models may eventually show a northwest shift in
upcoming model runs.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Lamers