Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
100 AM EDT Tue Aug 06 2019

Valid Aug 06/0000 UTC thru Aug 09/1200 UTC

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

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

...Overall Pattern Across the CONUS...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: Non-UKMET Blend
Confidence: Slightly above average

The stagnant pattern over the past couple days will begin to
change by the end of the week. The strong western ridge will begin
to erode with the approach of an amplified trough along the West
Coast by Day 3 (Thursday and Thursday Night). The ridge should
deamplify slightly with the ridge axis shifting into the Plains,
while a trough persists from the Great Lakes into the East Coast.

Overall model agreement with the mass field forecasts is good with
limited spread. The 12Z UKMET continues to show a stronger ridge
in the West and High Plains relative to the other models and the
bulk of the ensemble distribution. Only a few ensemble members are
similar, and the ridge has been verifying toward the weaker end of
the ensemble distribution over the past couple days. That may not
necessarily continue, but given the lack of ensemble support, the
UKMET is not included in the model preference at this time.
Otherwise, a blend of available models is preferred, with greater
weight given to the GFS QPF in the West and portions of the
Plains. The wetter GFS solution in the West makes sense given the
considerable northward push of moisture and available jet dynamics
for large scale ascent.


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

Lamers