Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
339 PM EDT Wed Jul 04 2018

Valid Jul 04/1200 UTC thru Jul 08/0000 UTC

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

12Z Model Preferences & Confidence Intervals
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAM/GFS initialization issues do not seem to degrade their short
range forecasts.


Convective low retrograding through TX
Second system retrograding towards southern TX Friday
Upper low crossing FL Friday/Saturday
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The guidance shows good agreement here, so prefer a compromise of
the available guidance (12z Canadian, 12z UKMET, 12z ECMWF, 12z
NAM, and 12z GFS) to deal with any lingering uncertainty on the
mass fields with above average confidence.  See our Quantitative
Precipitation Forecasts and Excessive Rainfall
Outlooks/Discussions for more details in this area.


Upper troughs near the Pacific Northwest & eventually Northeast
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The guidance shows good agreement with the evolution of these
upper features and their related cold front progression.  A
compromise of the 12z Canadian, 12z UKMET, 12z ECMWF, 12z NAM, and
12z GFS is preferred with above average confidence.


Possible convective low offshore the Carolinas
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: ECMWF/UKMET/GFS blend; confidence below average

The National Hurricane Center is monitoring this system for
tropical cyclone development.  The 12z UKMET/12z ECMWF are the
slowest to recurve the feature (keeping it close to the col in the
flow pattern) while the 12z Canadian/12z GFS are the quickest. 
The slowing trend in the Canadian and ECMWF was noticeable.  A
solution closest to a compromise of the 12z ECMWF/12z UKMET/12z
GFS is preferred with below average confidence due to the
considerable 00z global ensemble spread with its corresponding
surface low position.  See NHC outlooks for more information
regarding possible tropical cyclone formation.


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

Roth