Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
229 AM EDT Tue Jun 12 2018

Valid Jun 12/0000 UTC thru Jun 15/1200 UTC

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

00Z Model Evaluation...with Preliminary Preferences and Confidence
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

...Overall model diagnostic analysis for the CONUS...
 
General Preference: 00Z GFS; 00Z ECMWF
Overall Confidence: Average

---06Z UPDATE---

No major changes to the preliminary preference. The GFS and ECMWF
remain most consistent. The 00Z CMC has converged somewhat closer
to the GFS and ECMWF, and could be considered in a model blend.
The 00Z UKMET continues to show higher heights consistently
through almost the entire eastern CONUS.

---PREVIOUS DISCUSSION---

The general pattern over the CONUS over the next several days is
expected to evolve from a broad ridge over the southern half of
the country and zonal flow over the north, to moderate amplitude
troughs in the Northwest and Northeast, with a ridge axis in
between (and persistence of the ridge over the south). All models
show this pattern quite well, and there is fairly good agreement
overall with the mass fields of these models.

Model preference is a blend of the GFS and ECMWF, which is
consistent with model diagnostic discussions over the past several
model cycles. There are some slight differences (GFS slightly
faster with trough/front in the Northeast; different locations of
a weakness in the southern ridge), but overall the GFS and ECMWF
offer relatively similar forecasts and reasonable run-to-run
continuity.

Other models show some biases relative to model consensus that
have shown in recent model cycles. The 12 UKMET has higher heights
through much of the eastern CONUS for Wednesday and Thursday; the
12Z CMC shows a deeper trough over the West; and the 00Z NAM is
stronger (and slower) with the trough that pushes into the
Northeast and stronger with a secondary wave digging into the
Pacific Northwest on the backside of the western trough.

Confidence in the general pattern is above average, but overall
confidence continues to be rated as average given continued
uncertainty regarding convective outflows and timing that may
drive the forecast more than the overall pattern for a significant
portion of the country (Ohio Valley; Mid Atlantic; Southeast;
Southern Plains).


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

Lamers