Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1138 AM EST Fri Jan 10 2020
Valid Jan 10/1200 UTC thru Jan 14/0000 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: General model blend
Exception: Non-CMC central Rockies to central Plains after 12.12z
Confidence: Slightly above average
The latest model guidance continues to converge on a similar
solution with respect to the overall large scale pattern across
the CONUS through the next 3 days. Anomalously shortwave trough
currently digging across the southwest U.S. will eject out into
the southern Plains today with its corresponding surface low
deepening as it lifts northeast. This feature will lift along a
wavy stationary boundary draped from portions of the Plains
northeast toward the southern Great Lakes. Through the next 48
hours, model heights and mass fields are tightly clustered between
all the major global deterministic guidance and differences lie
mainly in the mesoscale, hi-res models regarding specific
timing/evolution of the convective elements. Beyond 48 hours as
the low lifts across the Northeast, some timing differences are
noted with the GFS racing out ahead of the other, non-NCEP models
but given the run to run trends, this may not be too out of
tolerance. So overall for the central/eastern U.S. storm system, a
general model blend should suffice.
For the western U.S. shortwaves, a couple compact systems will
affect the Pacific Northwest where the CMC remains the outlier.
Its slow/lagging solution becomes more apparent after 12.12Z as
the initial shortwave reaches the central Rockies toward the
central Plains where it's noticeably slower than the rest of the
deterministic guidance. In its wake, another shortwave drops
through the northwest where the GFS/ECMWF appear fairly tightly
clustered with just minor timing differences noted. With all this
in mind, leaned toward a general model blend across the CONUS
outside of a non-CMC blend after 12.12Z particularly across the
central Rockies to central Plains.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Taylor