Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
234 AM EDT Mon Jun 11 2018

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

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

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

...Overall model analysis for the CONUS...
 
General Preference: Non-UKMET Blend
Overall Confidence: Average

---06Z UPDATE---

The 00Z UKMET has trended closer to the model consensus, but still
has higher heights aloft through much of the eastern CONUS
beginning on Tuesday. These differences are substantial enough
that it is excluded from the preference at this time. Otherwise,
the 00Z CMC has also trended toward the model consensus and is
close enough in most respects that it is included in the
preference now.

---PREVIOUS DISCUSSION---

Models are in reasonably good agreement overall with their mass
fields. The most noteworthy differences are with the 12Z UKMET,
which connects two subtropical ridges (Southern Plains and
Bermuda) when other models show a clear weakness in the ridge over
the Southeast, and the 12Z CMC, which deepens a trough on the West
Coast from Wednesday into Wednesday Night more substantially than
other models (with a slower progression).

The preference, therefore, is for a blend of the NAM, GFS, and
ECMWF based on their mass fields. Overall the confidence in the
synoptic pattern is quite high given the broad agreement, but
confidence in the details continues to be lower than normal. This
is due to a likely continuation of MCS activity across the
northern half of the CONUS to the east of the Rockies. Although
the synoptic influence and flow aloft will be getting stronger,
which should increase predictability, many low-level boundaries
are likely to be strongly influenced by convective processes which
increases uncertainty in the forecast.

A blend that includes the ensemble means (GEFS and ECMWF) may also
be worthwhile as they will incorporate some of this uncertainty.


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

Lamers