Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
145 AM EST Sat Nov 10 2018

Valid Nov 10/0000 UTC thru Nov 13/1200 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...Day 1
            Blend of the 00Z GFS/ECMWF...Days 2/3
Confidence: Above Average...Day 1
            Average...Day 2
            Below Average...Day 3

Overall, very good agreement remains among the global
deterministic and ensemble guidance for the deep trough over the
Great Lakes Friday that becomes negatively tilted over the
northeastern CONUS Saturday before becoming vertically stacked
over eastern Quebec and Labrador Sunday. Another trough will shift
southeast from the northern Rockies Saturday and remain positively
tilted as it digs down the Plains to the central Rockies and Four
Corners region Sunday before shifting east onto the southern
Plains Monday and the lower/middle MS Valley on Tuesday.
Meanwhile, a deep layer ridge offshore the West Coast will shift
east and move into the Western U.S. by Tuesday.

Model spread increases in particular with the details of the
energy ejecting out across the southern Plains by Monday as the
00Z NAM ends up notably slower with the trough progression and has
a sharper trough hanging back over portions CO/NM compares to the
global models. The NAM becomes a slow outlier through early
Tuesday, and also ends up problematic downstream over the Eastern
U.S. as it ends up faster with its surface low evolution near the
East Coast. This is in part because the NAM is a little faster
with additional northern stream trough advancing across the
Midwest and Great Lakes region. The global models in general are
in better agreement, but the 00Z UKMET is a bit on the slow side
with the energy over the southern Plains/lower MS Valley region
and also the energy over the Midwest.

The models are in sufficient agreement through Day 1 that a
general model blend can be preferred, but the 00Z GFS and 00Z
ECMWF as a compromise will be preferred for the Day 2/3 time
period and also with respective support from their ensemble means.
The GFS is a little more progressive than the ECMWF across the
southern Plains/lower MS Valley region and also along the East
Coast with the upper trough evolution and related surface wave
activity, but a blend of the GFS/ECMWF solutions would best
approximate the global model consensus. However, confidence
becomes increasingly degraded by the Day 3 time period given the
increased model mass field spread in general across the Gulf Coast
and up along the East Coast.


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

Orrison