Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
245 PM EDT Mon Jun 25 2018

Valid Jun 25/1200 UTC thru Jun 29/0000 UTC

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

12Z model evaluation and preferences
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...Western U.S. to the High Plains...
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Preference: Blend of the operational models
Confidence: Above average

A lead trough will skirt through the northern Rockies and Plains
through Wednesday, followed by a more sharply digging trough over
much of the West on Thursday. The models are fairly tightly
clustered, including a 12Z trend toward the deeper GFS trough
structure aloft.

...Eastern U.S...
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Preference: 12Z GFS blended toward the 12Z Canadian and 12Z GEFS
Mean
Confidence: Average

A northern stream trough will move downwind of the Northeast
states Tuesday. The trough over the Midwest is simultaneously
reabsorbed into the westerlies and approaches the Mid-Atlantic
states to Northeast states. At the southern periphery of this
system latent heat release and convectively enhanced vorticity may
contribute to at least weak surface low development off the
Carolinas that would then move into the western Atlantic ahead of
the synoptic trough. The ECMWF has tended to be the most
aggressive with respect to surface low strength, often exhibiting
some convective feedback and not placing this feedback at the same
place/time from run to run. The operational GFS, while looking
good aloft, is perhaps too washed out at the surface, and has very
little reflection of the potential surface low. Thus, we recommend
blending the GFS with the middle-ground Canadian / 12Z CMC
solution and/or the GEFS Mean, to get a little better depiction of
an eastward extension of surface troughing off the coast and a
potential small spot low beginning Wednesday afternoon.


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

Burke