Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1256 PM EDT Wed Oct 31 2018

Valid Oct 31/1200 UTC thru Nov 04/0000 UTC

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

12Z NAM/GFS Model Evaluation...with Preliminary Preferences and
Confidence
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...Overall Pattern Across the CONUS...
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Preference: General model blend
Confidence: Slightly Above Average

12Z NAM/GFS remain in agreement with the 00Z consensus for the
synoptic flow pattern, QPF, and thermals (only the GFS) through
Friday. The strength of the shortwave entering the northern
Rockies Friday night is stronger in the 12Z NAM/GFS (GFS is
strongest) compared to the 00Z ECMWF/UKMET, so will monitor if
this is part of a new trend with the rest of the 12Z guidance. The
other note is the 00Z UKMET is more potent with the negatively
tilted trough in the northeast, closing it off Friday night over
Michigan while the other global guidance remains open through
Saturday.

The QPF is similar at this time over the southeast and northwest
with the exception of the 12Z GFS in the north for Day 3 with the
strong northern Rockies shortwave. Thermally the NAM becomes much
colder, as usual, by Day 3 in the northwest. Therefore, a general
model blend is acceptable for now with the few caveats mentioned.


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

Jackson