Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
138 AM EST Sun Feb 02 2020
Valid Feb 02/0000 UTC thru Feb 05/1200 UTC
...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...
00z Model Evaluation with Final Preferences and Confidence
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...Trough evolution over the Eastern U.S. through Sunday...
...Deepening coastal low tracking north offshore of New England...
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Preference: General model blend
Confidence: Above average
The models are in good agreement with the details of the
progressive trough moving through the eastern U.S. through the
remainder of the weekend. As the trough becomes negatively tilted
off the coast, a surface low pressure will deepen and lift
northeast well offshore, eventually impacting portions of
southeast Canada, especially the maritimes, on Sunday. A general
model blend is preferred.
...Deep longwave trough evolving over the Western U.S through
Wednesday....
...Surface wave activity developing over the lower/mid MS Valley...
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Preference: Blend of 00Z CMC/ECMWF and 00Z GEFS/12Z ECENS means
Confidence: Slightly above average
The 00Z NAM/GFS again just as it in previous runs continues to be
too progressive with the evolution of the deep longwave trough
evolution over the Western U.S. over the next few days.
Interestingly enough, the quick progression of the longwave
trough, as shown by the NAM/GFS, allows phasing to occur with
northern stream trough resulting in cooler thermals and also a
sharper northern axis to the QPF. Conversely, the 12Z UKMET
appears too slow with the trough progression toward the High
Plains by the end of the period. Though the 00Z UKMET was an
improvement. The remaining guidance led by the 00Z CMC/ECMWF, and
also the latest GEFS/ECENS means show generally good agreement
with the trough timing/depth and surface wave activity. A blend of
the non-GFS/NAM is preferred.
...Northern stream trough clipping the northern Plains Tuesday...
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Preference: Blend of the 00Z CMC/ECMWF/UKMET and 12Z ECENS
Confidence: Above average
There are subtle differences with respect to a northern stream
trough clipping the northern Plains into the Great Lakes region by
early Wednesday. Both the 00Z GFS/NAM are too amplified and a tad
slower allowing this piece of energy to phase with the longwave
trough to the south and west. This results in differences in the
thermals and QPF, especially Tuesday into Wednesday. It appears,
based on continuity and the overall speed of this trough, that a
flatter trough axis advancing east would seem most reasonable.
Therefore, a blend of the 00Z CMC/EC/UKMET and 12Z ECENS is
preferred..
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
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