Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
130 PM EDT Thu Aug 30 2018

Valid Aug 30/1200 UTC thru Sep 03/0000 UTC

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

12Z NAM/GFS evaluation with final model preferences and confidence
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...Overall Synoptic Pattern across the CONUS...
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Preference: Blend of the 12Z GFS/00Z ECMWF...more weight on GFS
Confidence: Average

The large scale upper pattern will feature a series of progressive
shortwaves advancing across southern Canada and the northern tier
of the U.S. through the short range period, with the general
tendency for a mean layer trough to focus over the Intermountain
West and a rather strong mid level subtropical ridge to remain in
place over the eastern U.S.

The 12Z NAM stood out the greatest from the remaining model
guidance regarding timing/amplitude of features and is considered
the least likely to verify through Sunday. Other timing
differences were noted with the 00Z UKMET across the Great Lakes
region concerning a cold front which is slower compared to the
non-UKMET guidance. Across the Southwest, some minor timing
differences were noted with the longitude of a trough axis by
Saturday/Sunday, with the NAM/GFS a bit ahead of the
ECMWF/UKMET/CMC, but with a blend between these models preferred.

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

Otto