Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
251 AM EDT Fri Mar 15 2019
Valid Mar 15/0000 UTC thru Mar 18/1200 UTC
...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...
12Z Model Evaluation Including Preferences and Confidence
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...Overall Pattern Across the CONUS...
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Preference: General model blend
Confidence: Above average
Models remain in excellent agreement overall on the synoptic
pattern over the CONUS for the next few days. A significant
extension of the North Pacific Jet will allow a highly amplified
ridge to build over western North America, and this should anchor
the synoptic pattern into early next week.
Normalized standard deviation fields from the ECMWF Ensemble show
limited spread over much of the West. The greatest sources of
model variability look to be with the progression of the cold
front through Florida this weekend, and precise timing of the
shortwaves that will be rounding the trough in eastern North
America. This has the greatest impact on forecast precipitation in
the vicinity of Florida. The 12Z ECMWF seemed too dry and thus
there was a greater weight placed on the 00Z GFS in those areas.
With respect to the northern stream shortwaves, the 12Z UKMET
seemed out of phase with the other models.
Other than incorporating those preferences into the forecast, the
approach was to use a general model blend. Expansive surface high
pressure settling into most of the CONUS this weekend should keep
most areas dry. Therefore, minor differences between models will
have a limited impact on the QPF.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Lamers