Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1259 PM EDT Wed Aug 29 2018

Valid Aug 29/1200 UTC thru Sep 02/0000 UTC

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

12Z NAM/GFS evaluation with preliminary preference
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...Overall Synoptic Pattern across the CONUS...
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Preference: 12Z GFS / 00Z ECMWF blend
Confidence: Slightly above average

The upper pattern will feature a series of progressive shortwaves
advancing through southern Canada and the northern tier of the
U.S. through Saturday, with an eventual evolution toward mean
troughing across the western U.S. while mid-level ridging
continues out East.

The biggest differences were noted across the western U.S. with
the 00Z CMC flatter with the degree of amplification through
Saturday compared to the remaining model consensus. The 00Z UKMET
was also noted to be a bit more amplified with energy advancing
through quasi-zonal flow into southwestern Canada Saturday morning
compared to the remaining consensus. Elsewhere, the NAM was noted
to be strongest with a disorganized low-level wave in the Gulf of
Mexico by Saturday morning.

A GFS/ECMWF blend is recommended given the best agreement to the
ensemble means and remaining deterministic guidance.

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

Otto/Weiss