Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
238 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 Model Evaluation and Preferences
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...Eastern U.S...
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Preference: Blend of 12Z NAM/ECMWF/Canadian
Confidence: Slightly Below Average

The closed low in the Ohio Valley phases with other troughing to
form a mean trough over the Northeast by Day 3. The NCEP guidance
has generally been deeper and somewhat slower in its depiction of
the resulting Day 3 trough. The ECMWF did trend a little bit
deeper in its 12Z run, but is still quite a bit faster and not as
deep as the operational GFS. Given clustering among the ECMWF,
NAM, and Canadian, it is difficult to keep the GFS in the list of
preferred models for this region, although differences really do
not become exaggerated until Day 3.


...Central U.S...
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Preference: 12Z ECMWF/UKMET/GFS
Confidence: Average

Troughing over the northern Rockies as of Friday will dig to form
a closed low over the Plains this weekend. The operational GFS,
ECMWF, UKMET fit fairly well into the ensemble mean consensus. The
GFS is a little more toward the fast and open end of the envelope
regarding the trough structure, and ends up looking a little fast
at the surface, but there is not strong reason to omit the GFS
from the preference - just keep in mind that the ECMWF/UKMET may
be slightly better preferred at this point. Certainly the NAM does
get to be a little bit of an outlier by Day 3.


...Northwest U.S...
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Preference: Blend of the operational models
Confidence: Above Average

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