Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1233 PM EDT Mon May 07 2018

Valid May 07/1200 UTC thru May 11/0000 UTC

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

12Z NAM/GFS Evaluation with preliminary model preferences
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GFS/NAM initialization errors are minimal and do not appear to
degrade their short range forecasts.


Upper level trough moving into the Pacific Northwest Tue-Thu
Lee cyclogenesis over the High Plains Wednesday-Thursday
Trough weakening while departing the East Tue-Wed
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
The guidance shows reasonable agreement with these systems, thus
prefer a compromise of the 12z GFS, 12z NAM, 00z ECMWF, 00z UKMET,
and 00z Canadian with above average confidence.


Shortwave ejecting through the Northern Rockies today,
then Northern Plains Tuesday and Upper Midwest Wednesday
Low consolidating over the Midwest tracking through Great Lakes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: GFS/ECMWF/UKMET blend; Confidence slightly above ave

The 00z Canadian is slow with this system, which is likely too
slow as the flow pattern is deamplifying and becoming quasi-zonal.
 Meanwhile, the 12z NAM is the strongest/most northerly with the
low crossing MI, which does force its precipitation forecast to
stray from the other guidance.  A compromise of the 12z GFS, 00z
UKMET, and 00z ECMWF is preferred 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

Roth