Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
130 PM EDT Sun Aug 12 2018

Valid Aug 12/1200 UTC thru Aug 16/0000 UTC

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

00Z model evaluation with final preferences
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...Overall Synoptic Pattern across the CONUS...
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Preference: Blend of 12Z GFS, 00Z ECMWF;
            weighted more to the GFS in the Northeast
Confidence: Slightly below average

As the pattern of the ridge over the Upper Midwest and trough over
the Northeast begins to break down, models are struggling to come
into agreement with the timing of a variety of waves in the
northern tier of states, particularly beyond T+48h forecast time
frames. The overall trend with the trough departing the Northeast
has been for it to speed up, so the 12Z GFS is preferred more in
that region to the slower ECMWF and CMC. With the next trough
emerging from the northern Rockies into the northern Plains, the
12Z UKMET and CMC appear to be much slower and are breaking down
the Northwest trough in a much different way as compared to the
more consistent GFS and ECMWF. The 12Z GFS has continued a trend
of a slightly deeper and slower trough, while the 00Z ECMWF is
just a bit slower than the GFS. Therefore a blend of those two
models is favored in this region. Elsewhere, model agreement is
better and a blend of the GFS and ECMWF should suffice.

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

Lamers