Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
246 PM EDT Sat Jun 06 2020
Valid Jun 06/1200 UTC thru Jun 10/0000 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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...Amplifying trough moving across the Northeast late Saturday and
Sunday...
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Preference: General Model Blend
Confidence: Above average
Overall, models are in good agreement through late Sunday --
indicating an amplifying trough moving across the Northeast
Saturday into Sunday, before moving into Atlantic Canada and east
of New England by late Sunday.
...Shortwave lifting from Utah into the northern High Plains
Saturday night...
...Upper low developing over western Canada on Sunday....
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Preference: UKMET, ECMWF and 00Z EC Ensemble Mean
Confidence: Average
The GFS is showing a more amplified shortwave lifting across
eastern Montana and western North Dakota Saturday night, with a
deeper low closing off east of the Canadian Rockies on Sunday.
The GFS also shows more phasing over central Canada between this
system and energy lifting out of the western U.S. trough described
below. The GFS then redevelops a deep low over Saskatchewan late
Monday. The UKMET and ECMWF both show a weaker low developing
farther to the north. While the NAM indicates more phasing than
the UKMET and ECMWF, it is farther west than the GFS.
...Closed low moving into the Pacific Northwest on Sunday...
...Upper trough moving from the Great Basin to the Plains Monday
and Tuesday...
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Preference: General Model Blend through 12Z Tuesday, followed by a
non-NAM blend
Confidence: Average
Overall, models are in good agreement -- showing an upper low
dropping southeast into the Pacific Northwest on Sunday. This
system is expected to transition to an open wave trough that will
move through the Great Basin into the Rockies late Sunday and
Monday. As described above, the GFS is less preferred with energy
lifting out of the trough and the evolution of a low over central
Canada; however, it is better clustered with the UKMET and ECMWF
with energy moving through the base of the trough from the Four
Corners region to the central Plains Monday night and Tuesday.
Overall, the models are fairly well-clustered through early
Tuesday, before the NAM becomes more of a less-amplified outlier
across the Plains.
...Cristobal...
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Preference: 15Z NHC advisory
Confidence: Refer to NHC products
The 12Z NAM and GFS are both well-clustered with the 15Z NHC track
guidance through Monday morning -- showing the system moving
through the northern Gulf of Mexico and making landfall over
southeastern Louisiana Sunday evening. The NAM remains fairly
well-clustered with the NHC track through early Tuesday across
Arkansas and Missouri, before racing out ahead of the NHC track
and the other models as the system moves toward the Great Lakes.
By early Tuesday, the GFS is slower than the NHC track and then
moves west of the track by late Tuesday. The 12Z UKMET is east of
the model consensus and NHC track as the system moves onshore and
then on Tuesday it makes a slower turn across the mid Mississippi
valley toward the Great Lakes. The 12Z ECMWF has shifted east and
shows good agreement with the NCEP models and NHC track through
early Monday. However, by early Tuesday it is slower, similar to
the UKMET.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Pereira