Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
145 PM EST Sun Feb 02 2020
Valid Feb 02/1200 UTC thru Feb 06/0000 UTC
...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...
12Z Model Evaluation with Latest Preferences and Confidence
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...Deep longwave trough evolving over the Western U.S. this week...
...Surface wave activity developing over the lower/mid MS Valley...
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Preference: Blend of the 12Z UKMET/ECMWF and 12Z GEFS/00Z ECENS
means
Confidence: Slightly above average
The 12Z GFS and to an extent the 12Z NAM just as it in previous
runs continue to be more progressive with the evolution of the
deep longwave trough evolution over the Western and Central U.S.
over the next few days. This drives a more progressive surface
wave evolution over the lower MS Valley and eventually the Gulf
Coast states by late Wednesday, with the GFS in particular
outrunning the guidance. The ensemble means led by the 12Z GEFS
and 00Z ECENS suites favor the less progressive consensus led by
the 12Z non-NCEP (UKMET, CMC and ECMWF) solutions. However, the
CMC has trended notably slower and is the slowest solution.
Accounting for the slower CMC, and the faster NAM/GFS, would
suggest favoring a solution toward the UKMET/ECMWF and the latest
ensemble means.
...Northern stream energy traversing the northern Plains/Great
Lakes...
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Preference: Blend of the 12Z ECMWF/GEFS mean and 00Z ECENS mean
Confidence: Slightly above average
There are subtle differences with respect to a northern stream
trough clipping the northern Plains, Great Lakes and northern New
England through Wednesday, but the UKMET overall appears a bit too
progressive with this feature. Additional northern stream energy
by late Wednesday will be also crossing southern Canada and
digging across the northern Plains. The non-NCEP models generally
have better support from the GEFS/ECENS means with this energy,
and overall with the lead energy outside of the UKMET. So, with
the NAM/GFS camp relatively out of tolerance, the preference will
be toward a blend of the 12Z ECMWF/GEFS mean and 00Z ECENS mean
with the northern stream energy going through midweek.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Orrison