Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
350 PM EDT Mon Oct 01 2018

Valid Oct 01/1200 UTC thru Oct 05/0000 UTC

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

12Z model evaluation including final preferences and confidence
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...Overall pattern across the lower 48...
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Preference: 12Z GFS / 12Z ECMWF blend
Confidence: Slightly above average

19Z update: Changes to the 12Z ECMWF were small, and adjustments
to the 12Z UKMET/CMC relative to their 00Z cycles were in the
direction of the GFS/ECMWF preference. Therefore, no changes to
the preliminary preference are recommended, other than to replace
the 00Z ECMWF with the 12Z ECMWF.

Through Thursday, the mid-level flow across the lower 48 will
continue ridging over the south-central and southeastern U.S. with
mean troughing along the West Coast. A number of shortwaves, along
with the forecast remnants of ongoing Tropical Storm Rosa west of
the Baja Peninsula, will move through the mean trough out west and
into the Great Plains. There were some minor timing and placement
differences noted with these progressive shortwaves but overall
agreement was pretty good through Thursday with the 00Z ECMWF and
12Z GFS best representing the better clustering seen in the
ensemble spaghetti charts. The biggest deterministic outliers were
the 00Z CMC which was noted to be slower with a strong surface
cyclone that will deepen over Ontario Wednesday night and the 00Z
UKMET which was more progressive with an upper trough in the
Northwest on Thursday.


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

Otto