Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1248 AM EDT Thu Jun 28 2018

Valid Jun 28/0000 UTC thru Jul 1/1200 UTC

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

00Z initial model evaluation...including preferences and confidence
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...Western US to the High Plains...
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Preference: 12Z GFS/12Z ECMWF blend
Confidence: Above average

Similar to the earlier runs, the 00Z NAM ends up being more
amplified and more progressive with the lead short wave that
tracks from Idaho into North Dakota between Friday afternoon and
Saturday afternoon, which results a surface front being a bit
faster over the Northern Plains by Saturday evening.  It develops
a closed upper low over Manitoba by the end of the short range
forecast period whereas the other models have more of an open
trough.  The 00Z GFS is much faster with a lead surface low over
Minnesota on Friday but appears to be in relatively good agreement
elsewhere.  The 12Z ECMWF is close to the ensemble means with the
mid level and surface systems, and is therefore the recommended
model for now.


...Eastern US...
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Preference: Non-UKMET model blend
Confidence: Above average

Both the 00Z NAM and 00Z GFS were close to the consensus with the
timing of the frontal boundary crossing the Northeast and Mid
Atlantic through Thursday afternoon, as well as the evolution of
the mid level ridging that builds from the Ohio Valley into the
Mid Atlantic through the period. There is some spread in the
placement of the mid level ridge by Saturday evening, with the 12Z
UKMET indicating the greatest degree of rising mid level heights.



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

Hamrick