Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
241 AM EDT Sat Jun 02 2018

Valid Jun 02/0000 UTC thru Jun 05/1200 UTC

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

00Z model evaluation along with final preferences
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...Slow moving upper trough over the Mid-Atlantic region today...
...Coastal low off of the northern Mid-Atlantic coast through
Monday morning...
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Preference: non 00Z UKMET blend
Confidence: Average

The biggest differences here are with the surface low forecast to
strengthen off of the northern Mid-Atlantic coast on Sunday and
track northeastward. While ensemble scatter low plot spread is
large and 00Z UKMET is not a total outlier...the non 00Z UKMET
models show decent agreement so a non 00Z UKMET blend will be
preferred for this system. While the 00Z ECMWF shifted much closer
to the coast with its surface low on Monday, it is still a usable
option when included with the 00Z NAM, GFS and CMC.

...Negatively titled upper trough crossing the upper MS Valley
Saturday night and Great Lakes on Sunday...
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Preference: 00Z NAM/GFS/ECMWF blend
Confidence: Average

Adjustments made in the 00Z models have been to slow the mid-level
trough axis a bit, but the 00Z UKMET/CMC stand out the most with
their depictions at 500 mb in being slower then the remaining
deterministic/ensemble consensus. Therefore, the 00Z NAM/GFS/ECMWF
appear best here given their agreement to the ensemble means. 
Ensemble spread is larger than average regarding 500 mb heights
and a surface low over the Great Lakes into Ontario, but will go
with the non 00Z UKMET/CMC deterministic consensus at this time.


...Mid-level vorticity maximum entering the Southwest U.S. on
Saturday...
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Preference: General model blend
Confidence: Slightly above average

The models show similarly with this system, with minor detail
differences best resolved with a general model blend. No
significant changes were noted with the 00Z ECMWF/UKMET/CMC
relative to their 12Z cycles.


...Upper trough reaching the Pacific Northwest Sunday/Monday...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: General model blend
Confidence: Above average

The models show minor differences with this system. Given the
relatively small spread and decent run to run consistency, a
general model blend is preferred to smooth out these smaller scale
differences. No significant changes were noted with the 00Z
ECMWF/UKMET/CMC relative to their 12Z cycles.


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

Otto