Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1230 AM EDT Mon Jun 10 2019

Valid Jun 10/0000 UTC thru Jun 13/1200 UTC

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

00Z Model Evaluation...with Confidence and Preferences
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...Overall Pattern Across the CONUS...
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Preference: Blend of the 00Z GFS and 12Z ECMWF
Confidence: Slightly above average

The elongating southern stream trough axis that extends from the
Ohio Valley south to the eastern Gulf coast region will continue
to steadily weaken through Monday, and a portion of the trough
will actually get suppressed down to the south and will become
focused over the northeast Gulf of Mexico through Tuesday. The
models are in very good agreement with the mass field evolution.
  
Meanwhile, a strong intrusion of northern stream height falls
crossing the northern Plains will eject across the Midwest and
Great Lakes region on Monday along with an attendant cold front.
All of the guidance shows the trough then quickly pivoting through
Northeast on Tuesday with additional northern stream shortwave
impulses digging down in behind it across the northern Plains and
Midwest in response to strong upstream ridging building along the
West Coast and into the Great Basin. The guidance is in reasonably
good agreement with the initial surge of height falls across the
Great Lakes and Northeast and with the details of the a strong
cold front that will cross through the eastern U.S.

Regarding the upstream energy, the 12Z CMC still occasionally
appears to be a tad too deep with the amplifying trough over the
Midwest Wednesday and Thursday, although all of the models agree
in having a rather strong upper trough with some suggestion of a
mid-level closed low developing near the western Great Lakes
region by Thursday. At the surface, low pressure developing over
the Midwest on Tuesday will shift east toward the Great Lakes
region by later Wednesday and Thursday. The 12Z UKMET is farthest
north and the strongest with the surface low. The 12Z CMC is the
weakest. The 00Z NAM, 00Z GFS and 12Z ECMWF are better clustered
although occasionally the NAM appears a little slow with its low
center. Meanwhile, the guidance all supports a separate low center
riding northeast up across the Southeast coastal plain and into
the Mid-Atlantic region Wednesday through Thursday along a frontal
zone. Model spread with this feature is quite modest.

Elsewhere, the larger scale ridging that builds along the West
Coast and the Great Basin over the next couple of days is expected
to break down as Pacific shortwave energy arrives late Wednesday
and Thursday. The 12Z CMC is a bit of a stronger outlier with its
shortwave trough at the end of the period crossing the West Coast.
The remaining guidance shows good timing and depth agreement.
  
Based on all of this, the model preference for the CONUS will be
toward a blend of the 00Z GFS and 12Z ECMWF considering notably
better ensemble agreement.


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

Orrison