Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
300 AM EDT Fri Sep 14 2018

Valid Sep 14/0000 UTC thru Sep 17/1200 UTC

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

00Z model evaluation including final preferences and confidence
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...Overall synoptic pattern across the CONUS...
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Preference: General model blend
Confidence: Slightly above average

A longwave trough along the west coast will remain in place into
Monday morning as a couple of shortwaves move through. One
shortwave is forecast to move across central CA on Saturday and
the base of a larger shortwave/closed low should cross into the
Pacific Northwest on Sunday. The former shortwave should spin up a
surface low along a front in the north-central U.S. on Sunday with
the 00Z UKMET adjusting closer to the model consensus compared to
its 12Z cycle. A general model blend is recommended for this
system given the relatively small differences noted in mass fields.


...Western Gulf coast trough/low nearing south Texas this
morning...
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Preference: non 00Z CMC blend
Confidence: Slightly above average

The 00Z CMC adjusted faster with the track of a disturbance in the
western Gulf of Mexico, approaching Texas. NHC has a 50 percent
chance of development over the next 48 hours as the system lifts
NW towards the Texas coast. Outside of the faster 00Z CMC, minor
timing differences remain in the guidance with the 00Z NAM a bit
slower and 00Z UKMET a bit stronger. A non 00Z CMC blend is
preferred here, led by the 00Z GFS and 00Z ECMWF.

Please continue to refer to the latest NHC discussions and
products for more detailed information on this system.


...Hurricane Florence...
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Preference:  00Z ECMWF/UKMET closet to 03Z NHC advisory

Most models are in good agreement until shortly after landfall
Friday when model divergence increases. The 00Z NAM is
south/slower and the 00Z GFS north/slower than the NHC track.
However, the 00Z ECMWF/UKMET adjusted closer to the NHC advisory
from 03Z, and while neither model agrees throughout the entire
short range period on the track of Florence, a blended approach
between the 00Z ECMWF/UKMET looks relatively close. The 00Z CMC is
also close to the NHC track but the 00Z CMC is a weaker outlier of
the deterministic guidance.

Please refer to the latest NHC discussions and products for more
detailed information on Hurricane Florence.

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

Otto