Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1247 AM EDT Wed Sep 11 2019

Valid Sep 11/0000 UTC thru Sep 14/1200 UTC

...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...

00Z Model Evaluation with Preferences and Forecast Confidence
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...Overall Pattern Across the CONUS...
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Preference: General model blend, strongest weights to...
            12Z ECMWF Ensemble Mean, 18Z GEFS Mean
Confidence: Slightly above average

Models are generally in very good agreement with their mass field
forecasts over the next few days, with limited model spread. The
deterministic models are all well within the ensemble envelope.
The flow pattern will deamplify considerably by the end of the
week, with a trough lifting into the Upper Midwest by Friday and
zonal flow settling into the northern tier of states thereafter.

Perhaps the greatest model variability is with the progression of
a trough from near the Bahamas westward into the Gulf of Mexico.
Models seem to be fairly similar in their depiction of the
amplitude of the wave (aloft and at the surface), but vary by as
much as 36-48h and 700km in timing. For this particular feature, a
median timing close to the ensemble means (00Z GFS and 12Z ECMWF
are fairly close) was preferred.

Otherwise, a general model blend with some weight toward the
ensemble means was preferred across the remainder of the CONUS.


Model trends at www.wpc.noaa.gov/html/model2.html
500 mb forecasts at www.wpc.noaa.gov/h5pref/h5pref.shtml

Lamers