Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1222 PM EDT Mon Aug 03 2020

Valid Aug 03/1200 UTC thru Aug 07/0000 UTC

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

12Z GFS/NAM Evaluation with Preferences & Forecast Confidence
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Any NAM/GFS initialization errors are small and do not appear to
degrade their short range forecasts.


Deep upper trough moving into the West Thursday
Southern stream trough moving into CA by Wednesday
Deep cyclone ejecting out of Southeast Canada
Shortwave moving through the Plains/Midwest/Great Lakes Wed-Thu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The guidance is in very good agreement on the details of these
systems, so a model blend of the 12z GFS, 12z NAM, 00z UKMET, 00z
Canadian, and 00z ECMWF is preferred with above average confidence.


Tropical Storm Isaias
~~~~~~~~~~~~~~~~~~~~~
The 12z GFS, and to some degree the 00z UKMET, are quicker to
eject Isaias northward through the East into Canada and best match
the 15z NHC track for this system.  For QPF purposes, the 06z FV3
SAR/GFS parallel and 12z ARW have aspects that appear useful for
the rainfall forecast from Monday into Wednesday.  See the latest
advisory from NHC for the latest on the track and thinking
regarding Isaias.


Model trends at <a href="https://www.wpc.ncep.noaa.gov/html/model2.shtml"><u>www.wpc.ncep.noaa.gov/html/model2.shtml</u></a>
500 mb forecasts at <a href="https://www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml"><u>www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml</u></a>

This product will terminate August 15, 2020:
www.weather.gov/media/notification/pdf2/scn20-58pmdhmd_termination.
pdf

Roth