Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1252 AM EDT Fri Aug 10 2018

Valid Aug 10/0000 UTC thru Aug 13/1200 UTC

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

00Z NAM/GFS evaluation with preliminary preferences
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

...Overall Synoptic Pattern across the CONUS...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: 00Z NAM, 00Z GFS, 12Z ECMWF blend
Confidence: Average

Trends since Thursday in the models have been toward convergence,
but some differences remain, namely with a closed low over the
Ohio Valley by Sunday morning into Monday. The 12Z ECMWF is
displaced a bit to the west along with its ensemble members while
the 00Z GFS / 18Z GEFS are quicker to the east. A blend of these
models is near the position of the 00Z NAM, 12Z UKMET/CMC.
Differences are small enough where a general model blend brings
about the favored middle ground.

Elsewhere, some differences with the position of a closed low over
the southern High Plains show up by Monday morning, with the 12z
ECMWF displaced a bit west of the remaining guidance but with
similar strength to the 00Z NAM/GFS. The 12Z UKMET was a bit
weaker here. The overall differences are not very large, however.

The biggest difference across the CONUS is due to a shortwave
tracking across southwestern Canada over the weekend with the 12Z
CMC slower/weaker with the mid-level shortwave. Good ensemble
agreement exists for a non 12Z CMC blend across the northwestern
tier of the U.S.

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

Otto