Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
237 AM EDT Tue May 29 2018

Valid May 29/0000 UTC through Jun 01/1200 UTC

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

00Z model preferences with confidence intervals
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Any NAM/GFS initialization errors to not seem to degrade their
short range forecasts.


Shortwave moving across the Northwest late Tuesday
Amplified trough moving into the West Thursday
Downstream surface low pressure in the Plains
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: Model blend; confidence above average

The guidance handles these systems and resultant low pressure
development in the Plains fairly similarly, within the noise of
the ensemble guidance.  A compromise of the 00z Canadian, 00z
ECMWF, 00z NAM, 00z GFS, and 00z UKMET is preferred with above
average confidence.


System moving across Plains/Great Lakes Tue-Thu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: Model blend; confidence slightly above ave

There are competing factors for this system's mid-level depth: A
building upstream ridge (supporting a system on the stronger side
of the guidance) and a building subtropical ridge rebounding to
its south (which could lead to a weaker system).  Timing issues
have resolved themselves in the 00z guidance.  To deal with depth
uncertainty, prefer a compromise of the 00z UKMET, 00z ECMWF, 00z
GFS, 00z NAM and 00z Canadian with slightly above average
confidence. 


Subtropical Tropical Depression Alberto
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: Model blend; see latest NHC advisory

The guidance shows better agreement concerning the future of
Alberto in the Lower 48.  See the latest advisory from the
National Hurricane Center for more about Alberto.


Southwest to Plains shortwave late Tue-Thu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: Model blend; confidence slightly above ave

The guidance brings a mid-level shortwave across the Southwest and
develops a terrain-induced or a convectively-induced shortwave in
the Rockies/central Plains Wednesday into Thursday.  Spread in
timing and depth appears to be reducing, as the ECMWF and Canadian
have trended stronger in their 00z runs.  A compromise of the 00z
UKMET, 00z ECMWF, 00z GFS, 00z NAM and 00z Canadian is preferred
for mass fields with slightly above average confidence.  See WPC
Quantitative Precipitation Forecast discussions for information on
the precipitation forecast.


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

Roth