Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
230 PM EDT Mon Jun 08 2020
Valid Jun 08/1200 UTC thru Jun 12/0000 UTC
...See NOUS42 KWNO (ADMSDM) for the status of the upper air
ingest...
12Z Model Evaluation Including Final Preferences and Confidence
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...Positively tilted trough over the Intermountain West that spins
off a low that crosses the central Rockies Monday night and lifts
over the Upper Midwest Wednesday...
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Preference: non-NAM blend
Confidence: Average
Differences begin to develop by early Tuesday as both the northern
and southern stream portions of the trough move east of the
Rockies into the northern and central High Plains. The NAM shows
a less amplified and more progressive northern stream trough
moving across the northern Plains on Tuesday, which in turn helps
to allow the developing southern stream low to linger over the
central Plains longer than the model consensus. By late Tuesday
and continuing through Wednesday, the NAM is a notably slow
outlier as the system moves across the central Plains and mid
Mississippi valley. In the northern stream, the GFS become a
relative outlier, with a more amplified trough/closed low
developing over the upper Midwest on Wednesday. With respect to
the timing of the associated front drifting east across the
northern Plains and upper, timing differences are minor through
late Tuesday before the NAM begins to move east of the consensus.
...Cristobal...
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Preference: ECMWF
Confidence: Average
Models are in good agreement into early Tuesday, with increasing
spread late Tuesday into early Wednesday. With its more
progressive upstream trough (described above), the NAM track moves
east of the model consensus as the system moves into the upper
Great Lakes Tuesday night into Wednesday morning. By Tuesday
night, as the system begins to interact with its more amplified
upstream trough, the GFS moves to the west side of the guidance.
As the system moves across the upper Great Lakes Tuesday morning,
the ECMWF has offered a consistent compromise between the GFS and
NAM positions.
...Southern Gulf of Alaska Low Stalling off the BC Coast Tuesday
night through Wednesday...
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Preference: General Model Blend
Confidence: Above Average
Overall, models are good agreement -- with no significant outliers
through early Thursday.
Pereira
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml