Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1217 AM EDT Mon Sep 10 2018

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

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

00Z Model Evaluation Including Preferences and Forecast Confidence
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...Overall Synoptic Pattern across the CONUS...
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Preference: General model blend
Confidence: Above average

Model suite continues to show very strong consensus with the
exiting former "Gordon" circulation through the eastern Great
Lakes/Eastern Canada and the lingering end of the trof tail across
South Texas that slowly leaks northeastward into the MS and Lower
Ohio valleys toward Wed, though highly stretched.   The main model
difference is in the eventual break down of the closed low off the
northern tip of Vancouver Island and its eventual, slow southward
drift as the strong height-falls/cross polar cold jet drives the
northern stream trof into SW Canada.  The CMC is generally slow to
weaken the closed low and is generally west of the mean axis of
the larger scale trof relative to the other guidance.   On the
flip side, the 00z NAM is shedding more energy on the east side of
the digging trof with the older center of the closed low, this
allows it to be fast ejecting toward the Rockies by early
Thursday.  A preference remains with a more centrist solution
presented by the 00z GFS/12z ECMWF/UKMET and the overall
ensembles.   Its not that the CMC or NAM are terribly out of
phase, but to resolve a stronger signal through the blending
process, and as such confidence reduces slightly to slightly above
average in the GFS/UKMET/ECMWF blend for the Northwest into the
northern High Plains Wed into Thurs.

...Hurricane Florence...
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Preference:  See NHC forecast discussion

There remains modest but reducing overall spread to the track of
Florence... and while the ECMWF/ECENS mean show greater overall
spread, the track is generally in line with the official 03z
forecast.  However, the operational run being much too fast; this
may be due to a slower evolution, southwest track of the
strengthening subtropical ridge...leading it to be further
south-east relative to the other guidance.  Only the 12z UKMET is
in line with the strength/placement of the ridge, and it is very
close to the 03z official NHC forecast.   The GFS-parallel (FV3)
is closer to the official forecast (especially at 84hrs and after)
than the operational.   As such a compromise of the FV3-GFS and
UKMET may be best deterministic model guidance to match the
forecast.


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

Gallina