Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
254 PM EDT Tue Oct 08 2019

Valid Oct 08/1200 UTC thru Oct 12/0000 UTC

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

08/12Z Model Evaluation with Preferences and Forecast Confidence
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...Energy amplifying over Central Appalachians/Mid-Atlantic...
...Deepening surface low pressure off the East Coast...
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Preference: 08/12Z ECMWF and 08/12Z GFS Blend
Confidence: Average

The 12Z suite of NCEP guidance showed a trend towards a somewhat
deeper, broader solution with respect to the low deepening off the
northeast U.S..  The ECMWF and UKMET also nudged this way...which
left them in fairly good agreement with the NCEP guidance.  The
deeper solutions appear to have the greatest deep
convection/latent heat influence and given the strength of the
moisture feed, there is growing confidence toward this evolution.
The ECMWF ensemble means tended to support the 12Z operational run
while the 12Z GFS was on the eastern side of the envelope of
solutions...although the difference is pretty minor.  The amount
of interaction between the more-baroclinic low and a trailing
system originating closer to Florida will influence the ultimate
evolution of the low off the east coast.  That keeps the
confidence in the forecast no higher than average. 


...Deep upper trough/closed low amplifying over the West...
...High Plains cyclogenesis...
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Preference: General model blend
  After 11.00z: Lower weight in the GFS 
Confidence: Above average

Models continue to show very strong agreement with the evolution
of the deep latitude, positive tilt trof through about
10.00z...with the agreement being strengthened by the adjustments
made by the ECMWF at the 08/00Z and the 08/12Z runa.  The 12Z GFS
maintained a slower solution given a more compact evolution to the
deepening low into the Central Plains. With stronger overall
agreement in the NAM, UKMET, CMC and the slowing of the GFS...it
is harder to have confidence in higher weighting in the blend.  
So WPC preference is a general model blend with above average
confidence before 60hrs.   After 60hrs (11.00z), WPC preference
would be to still be a general model blend but lower weighting to
the operational ECMWF and GFS. 


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

Bann