Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1207 PM EDT Fri Jun 22 2018

Valid Jun 22/1200 UTC thru Jun 26/0000 UTC

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

12Z NAM/GFS Evaluation and Preliminary Preferences
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...Eastern U.S...
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Preference: Blend of 12Z NAM/GFS

The NCEP guidance is more amplified in the upper trough compared
to other guidance. This seems to fit in with what is an amplified
northern stream flow, and the good clustering of the GEFS with
GFS, NAM gives us some confidence in steering toward the NCEP
guidance as a preference here, although confidence is only
average. The operational GFS is perhaps too amplified / sharp, or
at least is exaggerated with respect to the NCEP consensus, so
blending it with the lower amplitude and more progressive NAM is
recommended, especially by Day 3.


...Central U.S...
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Preference: 12Z GFS / 00Z ECMWF

Troughing over the northern Rockies as of Friday will dig to form
a closed low over the Plains this weekend. The GFS, ECMWF and
their respective ensembles show good clustering, which makes this
preference an easy choice.


...Northwest U.S...
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Preference: Blend of the operational models

A medium wavelength trough will enter the Pacific Northwest on
Days 2 and 3. These types of systems are usually well handled, and
model consensus is strong this cycle.

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

Burke