Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1252 AM EDT Mon Mar 09 2020
Valid Mar 09/0000 UTC thru Mar 12/1200 UTC
...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...
00Z Model Evaluation with Preferences and Confidence
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...Overall Pattern Across the CONUS...
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Preference: General model blend through 48 hours; blend of
ECMWF/UKMET/ECENS day 3
Confidence: Slightly above average
A couple areas of focus for model diagnostics across the CONUS in
the short term, one is the approach of the closed upper level low
over the southwest U.S. where over the last several model cycles,
the GFS has slowed toward the rest of the consensus and
preference. The 00Z GFS continued that theme and now appears in
line with the rest of the guidance (and slower than the 18Z GEFS
mean). For mass field purposes, a general model blend can be
applied to these areas now.
In the northern stream, a shortwave trough swings through the
northern Plains toward the Upper Midwest and Great Lakes region.
The 00Z GFS is atypically slower than the rest of the guidance
while the 12Z CMC races ahead of the other deterministic guidance.
The ECMWF and to some degree the UKMET offer the more reasonable
and consistent evolution and trend, so a blend heavy on those two
models is preferred. At the end of the forecast period, another
stronger shortwave trough dips down into the northern Plains.
Here, the GFS is more amplified and faster as the wave digs down.
So for the northern stream systems, less inclusion of the GFS is
preferred.
Rainfall placement in the Ozarks and lower Mississippi River
region late on Day 3 is the subject of some disagreement with
higher uncertainty and less consistency seen in the run to run
model cycles. Questions related to the northward push of greater
instability and interactions with a lagging/slowing front remain
key for the eventual potential higher QPF swath. For now, a blend
heavy on the ECMWF/ECENS looks reasonable.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Taylor