Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1219 PM EST Wed Mar 04 2020
Valid Mar 04/1200 UTC thru Mar 08/0000 UTC
...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...
12Z NAM/GFS evaluation with preliminary preferences and confidence
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...Eastern half of the nation...
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Preference: Blend of 12Z NAM, 00Z ECMWF and 00Z UKMET
Confidence: Slightly above average
Across the eastern U.S,, a surface low will track into the western
Atlantic as a strong mid-level trough sweeps across the East
Coast. The 00Z CMC has been and continues to be slower with the
upper trough, allowing for a more western surface low track
offshore of the East Coast. The 12Z GFS appears a bit faster and
north with the core of the upper trough that passes over the Great
Lakes and Northeast. Ensembles support is greatest toward the
middle of the latest spread, with decent run to run consistency
supporting the middle ground. A blend of the 12Z NAM, 00Z ECMWF
and 00Z UKMET is likely best across the eastern half of the nation.
...Western half of the nation...
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Preference: General model blend
Confidence: Slightly above average
Across the western U.S., a longwave trough will approach the
Pacific Northwest on Thursday along with an associated cold front.
There are some minor differences within the base of the trough as
it approaches northern California with the 12Z GFS and 00Z UKMET
slower and more amplified with vorticity compared to the 12Z NAM,
00Z ECMWF and 00Z CMC. The differences are small enough and wash
out as the feature moves inland, supporting a general model blend.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Otto