Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1132 PM EST Sun Feb 09 2020
Valid Feb 10/0000 UTC thru Feb 13/1200 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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...Digging trough over the Great Basin/Southwest ejecting east
toward the southern Plains by Tuesday...
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Preference: Blend of ECMWF/GFS/CMC through 12.12Z, then ECMWF/GFS
blend
Confidence: Slightly above average
Closed upper level low currently over southern California will
slowly eject into the Southwest US and eventually the
south-central Plains through the next 3 days. Through 48-60 hours,
the ensemble and deterministic guidance is in above average
agreement and has shown consistency the past several model cycles.
Excluding the UKMET which was off in timing the progression of the
system and the NAM which was a bit too deep, the ECMWF/GFS/CMC
offer a fairly good approach that is similar to the ECENS/GEFS
means. Toward Day 3, the GFS/GEFS becomes a bit faster compared to
the ECMWF/ECENS, but overall a blend of the two solutions would
yield a reasonable approach at this time.
...Shortwave crossing British Columbia Monday night...
...Energy dropping southeast across the northern Rockies Tuesday...
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Preference: General model blend through 12.00Z; ECMWF/GFS blend
thereafter
Confidence: Slightly below average
Two shortwaves will drop through the northern stream energy across
the Northern Plains and Great Lakes region in the forecast period.
The first wave swings through the northern Rockies Monday and
splices off with some energy ejecting eastward toward the Great
Lakes while another piece phases somewhat with the closed low over
the Southwest US. Here the latest guidance has come into
relatively good agreement with this idea such that a general model
blend can be used through 12.00Z.
Beyond that time frame, another shortwave trough quickly drops
into the northern Rockies and becomes absorbed within the
developing larger scale troughing over the central US by the end
of Day 3. The CMC becomes too deep and slow over the Upper
Midwest. While the GFS is a step ahead of its ensemble mean, there
is reasonably good agreement and clustering such that the
operational ECMWF/GFS seem like a good approach for Day 3 at this
time.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Taylor