Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
317 AM EDT Mon Jun 18 2018

Valid Jun 18/0000 UTC thru Jun 21/1200 UTC

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

00Z Model evaluation including preferences and forecast confidence
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...Overall model diagnostic analysis for the CONUS...
......exception(s) in section(s) below......
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Preference: Non-GFS blend
Confidence: Above average thru 20/00z...average afterward

Overall, the 00Z guidance continued to show good agreement in
their large scale flow pattern over North America through about
20/00Z, including placement and timing of shortwave energy moving
out of the Rockies and into confluent flow downstream.  In
addition, there was generally good agreement with flow over the
eastern part of North America.

Some of the concerns from earlier about the 17/12Z GFS run are
still in play in the 18/00Z run with respect to the closed low
initially over the Great Basin.  The amount of upstream ridging
depicted by the GFS made it a strong outlier and this resulted in
a deeper/more southern placement of the low (or its remnant
energy) compared with other models.  It is worth that the ECMWF
and GFS start to converge on the placement of the closed H50 low
by the 21/12Z.

With the 18/00Z ECMWF largely maintaining continuity and the
UKMET/CMC making subtle shifts towards the ECMWF solution, will
not make any changes to the previous model preference of a non-GFS
solution.


...Broad TUTT Cell and low level easterly tropical wave
progressing through Western Gulf
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Preference: 17/12Z ECMWF/CMC blend
Confidence: Below average

Large model spread remains both in the deterministic guidance and
internal ensemble members with respect to the development of this
TUTT and surface wave. 

The 50 member ECENS suite showed a large variety of potential
outcomes.  The 00Z guidance still tends to suggest a stronger
ridge over Mexico as well as over the Eastern Gulf with increased
energy shed to the northern stream.  This still leaves the 18/00Z
CMC on the slow side of the solution with the 18/00Z ECMWF.  The
GFS appears to be too weak with the feature.

Overall the trend continues to tip toward a stronger/deeper more
consolidated response, but not as dramatic as the ECMWF or UKMET. 
As such, will continue to favor the latest EC/CMC solutions with
below 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

Bann