Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
241 PM EDT Sun Jun 30 2019

Valid Jun 30/1200 UTC thru Jul 04/0000 UTC

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

12Z Model Evaluation...with Confidence and Preferences
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...Overall Pattern Across the CONUS...
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Preference: Non-NAM blend
Confidence: Slightly above average

Models are in good agreement with the synoptic pattern and their
mass fields are relatively similar. The largest differences are
with the 12Z NAM, which by the end of the period shows the
troughing over the Northwest beginning to edge a bit faster off to
the east toward the northern Rockies and northern High Plains.
Also, the NAM tends to occasionally appear to be too aggressive
with some of its vort energy rounding the top of the mid-level
ridge axis over the central Plains and Midwest which is expected
to gradually beginning breaking down a bit over the next few days.
There is very good model mass field agreement with the details of
the trough over the Northeast that begins to gradually weaken and
lift out, and also with the details of the weak mid-level
trough/closed low feature over the southern Plains. Based on all
of this, a non-NAM blend will again be preferred.


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

Orrison