Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1251 PM EDT Sat Nov 02 2019

Valid Nov 02/1200 UTC thru Nov 06/0000 UTC

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

...12Z Model Evaluation with Preferences and Confidence...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

...Overall Pattern Across the CONUS...

Preference: General model blend, weighted less to 12Z GFS/NAM
            after Monday morning (04.12Z)
Confidence: Slightly above average

Model agreement on the overall synoptic pattern is very good, with
the available deterministic models generally within the envelope
of ensemble spread. The ensemble spread itself is relatively
small, with ECMWF ensemble 500mb height spread near or below the
previous 30-day average across the entire CONUS over the next few
days. Therefore, a general model blend is preferred.

There are some important detail differences, primarily with
shortwaves moving through the stronger flow at the base of a broad
trough from the Northern Plains, to the Midwest, to the Northeast.
This affects the placement of some areas of precipitation --
including one swath in the Upper Midwest on Sunday Night and
Monday, and another near the Northeast coast on Tuesday. In
general, the placement of areas of precipitation was near a median
position of the available models, given a lack of identifiable
bias from any individual models and the very minor differences in
the mass fields overall.

By Monday Night and Tuesday, less weight was placed on the GFS and
NAM. Both models begin to show a trend toward lower heights than
the global model consensus, particularly with one wave in the
Northeast, and another in the Intermountain West. This affects
placement of precipitation near the Northeast coast on Tuesday,
and how quickly a closed upper level low near northern Baja
California ejects east.

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

Lamers