Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
139 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 Preliminary 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: 12Z UKMET/00Z ECMWF and 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 with this system and energy
lifting out of a trough that is moving through the western U.S.,
with a redeveloping low over Saskatchewan late Monday. While the
NAM indicates more phasing than the UKMET and 00Z 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 00Z
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 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 00Z ECMWF is west of the NCEP
models and NHC track across Louisiana and Arkansas and then slower
as the system turns toward the northeast on Tuesday.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Pereira