Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
339 PM EDT Thu Jun 20 2019

Valid Jun 20/1200 UTC thru Jun 24/0000 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: General Model Blend
Confidence: Average

19z update: No significant changes noted with the rest of the 12z
guidance now available. The GFS still appears to be faster
compared to the rest of the guidance with the trough out in the
west/central plains on day 3 while the CMC is still slower. A
general model blend of the mass fields is still preferred at this
time.

---previous discussion---
Troughing over the northeastern US and longwave troughing over the
western US start out the forecast period across the CONUS and over
the next 3 days, generally troughing will stay across the interior
west and central Plains with ridging extending from the Gulf Coast
states through the Great Lakes. Troughing will also be confined to
the Northeast US and New England.

In general, through 48-60 hours, the models exhibit fairly good
agreement and run to run consistency. The biggest differences
develop by Day 3 with respect to the troughing over the Rockies
and Central Plains. Here the latest GFS is faster than most of the
other guidance and also is much deeper/more amplified than the
GEFS mean. Meanwhile, the ECMWF is also a bit more amplified, and
even closes off by the end of Day 3, and is much stronger than its
ensemble mean. The CMC is the slowest of the deterministic models
with the trough axis and a bit outside the model spread. At the
surface, the models are in fairly good agreement with the stronger
low off the Northeast coast as well as a deeper low developing by
Day 2 over the northern Plains.

With this in mind, a general model blend should yield favorable
results with the mass fields given the faster GFS, slower CMC, and
stronger ECMWF in play.

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

Taylor