Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1213 AM EDT Fri May 11 2018

Valid May 11/0000 UTC thru May 14/1200 UTC

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

00Z NAM/GFS evaluation with preliminary model preferences
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAM/GFS initialization errors do not seem to degrade their short
range forecasts.


Broad upper trough over the Gulf of Mexico/FL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: Non-GFS blend; confidence above average

A broad upper trough moving east across the Gulf of Mexico closes
off a mid-level center off of western FL in 2-3 days.  The 00z GFS
appears to be suffering from some gridscale feedback in a couple
days which then wraps/couples with the mid- to upper-level center,
producing a low offshore western FL none of the other
deterministic guidance advertises.  A compromise of the 00z NAM,
12z UKMET, 12z Canadian, and 12z ECMWF is preferred with above
average confidence.


Broad mid-level cyclone parked across the West
Broad upper trough across eastern Canada & the Northeast
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The guidance is in good agreement with these systems/in these
areas.  A compromise of the 00z GFS, 00z NAM, 12z ECMWF, 12z
Canadian, and 12z UKMET is preferred with above average
confidence.  This should effectively deal with the 00z NAM's
strong bias with the western system effectively.


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

Roth