Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1244 PM EDT Sun Jun 23 2019

Valid Jun 23/1200 UTC thru Jun 27/0000 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: ECWMF/UKMET/CMC blend
Confidence: Average

Troughing over the interior west and central Plains anchored by an
anomalous shortwave over WY/CO will work northeast today and
tonight, becoming negatively tilted over the Upper Midwest.
There's above average confidence and consistency in the latest
model suite for this feature that a general model blend would
suffice for the large scale mass fields.

For Day 2/3, another anomalous closed upper level low will
approach the Pacific Northwest slowly and this will gradually lead
to downstream ridging over the eastern 2/3 of the CONUS. While
most of the deterministic models handle the closed upper low
fairly well, the deterministic models differ downstream with the
strength of the ridge and whether any convective complexes could
introduce some shortwave troughing over the lower Ohio and TN
Valleys.

By Day 3, both the 12z GFS and NAM show that a shortwave
originating out of Texas will work northeast and become more
pronounced over TN/KY by Wednesday evening. Meanwhile, the
ECMWF/UKMET/CMC are absent of this feature (UKMET may have a
slight reflection of it) and instead indicate more ridging/warmer
temps aloft. The NAM seems to be keying on convective complexes
developing out of the central Plains helping to reinforce or
strengthen this shortwave while the GFS seems to be just
amplifying the TX shortwave much more than the rest of the
guidance.

For now, given the strength of the troughing out west and
potential for an overachieving southern/southeast ridge, will lean
on the ECMWF/UKMET/CMC solutions.


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

Taylor