Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
126 AM EDT Tue Jun 25 2019

Valid Jun 25/0000 UTC thru Jun 28/1200 UTC

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

00Z NAM/GFS Evaluation...with Preliminary Confidence and
Preferences
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...Overall Pattern Across the CONUS...
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Preference: General model blend
Confidence: Average

Flow across the CONUS begins with a departing, negatively tilted
shortwave over the Great Lakes region and a large closed mid-level
low west of southern British Columbia with zonal flow between the
two features. By the end of the week, from the middle and lower
Mississippi Valley to the East Coast, a weak/broad trough sets up
with ridging centered over New Mexico and the western Atlantic.
There is excellent large scale model agreement on the pattern
across the lower 48 with minimal spread in the synoptic scale
features.

The disagreements come from smaller scale embedded vorticity
maxima, with convectively driven origins, and their interactions
with relatively weak synoptic scale boundaries at the surface from
the Ohio Valley into the central and northern Plains. No single
model stands out significantly but there is broad agreement from
the UKMET/NAM and then with the GFS/ECMWF/CMC regarding QPF maxima.

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

Otto