Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1250 AM EDT Thu Sep 12 2019

Valid Sep 12/0000 UTC thru Sep 15/1200 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
Confidence: Slightly above average

The synoptic pattern over the CONUS features an anomalous upper
level trough over the northern Rockies and northern Plains with a
strong ridge over the southeast U.S. Another closed upper low will
move onshore the Pacific Northwest during the forecast period
while an area of disturbed weather and disorganized
showers/thunderstorms over the Bahamas will slowly drift westward
toward Florida by Day 3.

The latest model guidance is in above average agreement across the
northern tier of the US during the next 3 days with the evolution
of the upper level shortwave as it lifts northeastward into the
Hudson Bay area. A surface low deepening over the area is also
well represented and tightly clustered with the latest
deterministic guidance. In general, mass fields across the CONUS
are in good agreement such that a general model blend suffices.

The largest model variability exists with the tropical disturbance
near the Bahamas. Over the next 3 days, most of the global
deterministic guidance shows slow development. The 00Z GFS is a
faster and westward solution, with its low reaching Louisiana by
84 hours. Meanwhile, the UKMET is the furthest east, with its low
position near Jacksonville at 84 hours. The CMC/ECMWF offer a good
proxy for consensus at this time.


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

Taylor