Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
255 AM EDT Wed Oct 10 2018

Valid Oct 10/0000 UTC thru Oct 13/1200 UTC

...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...

00Z Model Evaluation...with latest preferences and confidence
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...Overall Pattern Across the CONUS... 
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Preference: Blend of the 00Z GFS/UKMET/ECMWF
Confidence: Slightly above average

There are some minor differences with the longwave trough position
and strength by Wednesday evening across the upper Midwest, likely
due to how quickly the northern and southern stream energy phases.
The 00Z NAM is a bit stronger and more pronounced with the tilt of
the shortwave, closing off over the Dakotas. Meanwhile, the 00Z
GFS lines up reasonably well with the 00Z CMC/ECMWF/UKMET
solutions which keep the trough a tad more open as it lifts across
the northern tier. With the surface low track across the Upper
Midwest and Great Lakes region, the guidance is very well
clustered.

In the wake of the upper Midwest trough/closed low, there will be
two additional northern stream shortwaves dropping southeast from
Canada, with one crossing the northern Plains and Midwest Friday
through Saturday, and then arriving across the Eastern U.S. on
Sunday. A secondary shortwave will then amplify down toward the
northern High Plains by Sunday. The 00Z GFS becomes a fast outlier
with the first of these two shortwaves as the remaining guidance
led by the 00Z NAM/CMC/UKMET/ECMWF solutions are slower.
Meanwhile, regarding the secondary shortwave evolution into the
northern Plains by Sunday, the 00Z NAM becomes a bit of a deep
outlier.

Elsewhere, the guidance all supports a closed low evolution off
the southern California coast by Friday and Saturday. The 00Z NAM
tends to retrograde more energy off to the west compared to the
global models.

Based on the latest model spread and clustering of solutions
across the CONUS for this period, a blend of the 00Z GFS, 00Z
UKMET and 00Z ECMWF will be preferred.


...Hurricane Michael...
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Preference: See the latest NHC forecast advisory

Powerful Hurricane Michael will lift north and be crossing the FL
panhandle within the next 24 hours, and will then rapidly recurve
northeastward across the interior of the Southeast and the
southern Mid-Atlantic states through the 48 hour time-frame. The
00Z ECMWF trended faster with this cycle and now is very close to
the 00Z GFS with the track of Michael through 48 hours.
Thereafter, as the storm exits the Mid-Atlantic coast, the ECMWF
begins to edge toward being the slowest solution. The 00Z CMC also
has a track very comparable to the GFS/ECMWF camp through the same
time frame, but the CMC is overall a weak outlier with Michael
after landfall. Meanwhile, the 00Z NAM and 00Z UKMET solutions are
the fastest solutions with the track of Michael, although the NAM
takes the storm a bit right of the global model consensus. The 03Z
NHC forecast track is a bit faster than the model consensus and is
close to a blend of the GFS/ECMWF and UKMET through about 48
hours, and then is more like the UKMET thereafter.


...Hurricane Sergio...
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Preference: See the latest NHC forecast advisory

The global models all continue to agree on recurving Hurricane
Sergio off to the northeast toward the central Baja California
peninsula over the next couple of days, with the storm likely
making a landfall here on Friday. Thereafter, the storm will begin
to lose its identity as it traverses northwest mainland Mexico,
but its moisture and remnant mid-level energy will impact portions
of the Southwest and also the southern Plains. The 00Z CMC/ECMWF
solutions are the slowest, with the 00Z GFS the fastest. The 00Z
NAM and 00Z UKMET split the difference, but the UKMET is only a
little slower and to the right of the GFS. The 03Z NHC forecast
track is a bit faster than the model consensus and is just to the
right of the GFS solution, and only a little faster than 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

Orrison