Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
125 AM EST Sun Mar 01 2020
Valid Mar 01/0000 UTC thru Mar 04/1200 UTC
...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...
00Z Model Evaluation with Preferences and Confidence Intervals
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Any NAM/GFS initialization errors do not appear to degrade their
short range forecasts.
Shortwave near the Pacific Northwest on Tuesday
Shortwave over the northern Plains/Midwest by Tuesday
Shortwave crossing the Upper Midwest/Great Lakes by Monday
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The guidance shows good agreement with these systems with any
variations noted within the spread of the global ensemble
guidance. A compromise of the 00z GFS, 00z NAM, 00z ECMWF, 00z
UKMET, and 00z Canadian is recommended with above average
confidence.
System moving down CA on Sunday
then progressing near the western/central US-Mexican border
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Preference: General model blend similar to a weakened 00z NAM
Confidence: Slightly above average
The GFS remains a quick outlier with this system, even when
compared to its 00z ensemble mean (one of its typical biases).
The 00z NAM splits the difference while the ECMWF, UKMET, Canadian
all slowed down on their 00z runs. The NAM remains deeper than
the remainder of the other guidance (one of its typical biases).
Despite the guidance spread, all the guidance falls well within
the 12z global ensemble spread at 500 hPa (using the 5640 meter
height line as a guide). A compromise of the available guidance,
similar to a weaker/less cold form of the 00z NAM with a more
southeastern surface low in the Gulf rather than over TX, is
preferred with slightly above average confidence.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Roth