Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1254 PM EDT Mon Sep 30 2019

Valid Sep 30/1200 UTC thru Oct 04/0000 UTC

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

12Z Initial Model Evaluation with Preferences and Forecast
Confidence
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...Overall Pattern Across the CONUS...
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Preference: 00Z ECMWF/ECENS/UKMET
Confidence: Slightly below average

The 12Z NAM remains much more progressive with the ejection of the
trough currently over the Northwest CONUS as it pushes across the
northern Great Plains starting on Day 2. The 12Z GFS is also
faster than the consensus with this ejection, but is not as
progressive as the 12Z NAM. However, the 12Z GFS continues a long
trend in the GFS of having a shallower trough in the west by
04/00Z which results in less precipitation over OR compared to
other global guidance. Therefore, the 12Z GFS and NAM are
de-emphasized in the preferred blend.

The 00Z ECMWF and UKMET share strong similarities in how they
advect the strong shortwave trough as it rounds and tops off
eastern CONUS ridge as well as a more amplified trough down the
West Coast on Thursday. These models are preferred at this time.

A heavy rain event across the middle of the country is still
expected through Wednesday night as the trough taps gulf moisture
and plenty of energy from the above normal temperatures that have
been pervasive under the ridge centered over the eastern CONUS.


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

Jackson