Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1126 AM EST Wed Nov 06 2019
Valid Nov 06/1200 UTC thru Nov 10/0000 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 through 10.00Z
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: General model blend through 08.12Z; ECMWF/GFS blend
through 10.00Z
Confidence: Slightly above average
Arctic shortwave and closed low shearing out of the Southwest
currently will phase across the Ohio Valley and further amplify
across the eastern Great Lakes/Mid-Atlantic supporting surface
cyclogenesis in the next couple of days. The most recent guidance
continues to be more agreeable with the surface low position
offshore Maine early Friday morning as shortwave energy and
troughing over the northern Plains and Great Lakes region becomes
negatively tilted. At 500 mb, there is fairly good clustering with
the available deterministic guidance and low ensemble spread. As
that troughs digs over the Northeast, upstream ridging becomes
more pronounced Friday-Saturday. A subtle/weak shortwave is
forecast to ride the ridge and this is where model guidance
differs somewhat. The GFS flattens the ridge the most while the
ECMWF/UKMET offer a stronger ridge solution. Elsewhere across the
CONUS, another clipper shortwave will drop through the northern
plains late Friday into Saturday morning, but the available
guidance seems to have clustered well with this feature. With all
this in mind, a general model blend is preferred through the first
48 hours, followed by heavier weight toward a GFS/ECMWF blend for
Day 3 with slightly above average confidence.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Taylor