Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
334 PM EDT Mon Jun 03 2019

Valid Jun 03/1200 UTC thru Jun 07/0000 UTC

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

12Z Model Evaluation with Confidence and Preference
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...Overall Pattern Across the CONUS...
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Preference: General model blend
Confidence: Slightly above average

19z update: No significant differences noted with the rest of the
12z guidance, so will keep the preference for a general model
blend.

---previous discussion---
Across the CONUS through the next 3 days, fairly zonal pattern
will remain in place with weak, low amplitude wave moving across
the southern US. By the end of the forecast period, an anomalous
upper low will drop into the Pacific Northwest. Model agreement in
the large scale mass fields is above average with above normal
confidence with a general model blend preference for this cycle.

In the northern stream energy, there is excellent model agreement
with the eventual exiting of the closed upper low near James Bay.
This will be followed by relative quiet period of shortwaves
before another one shears into the Pacific Northwest. Across the
central Plains, more subtle / mesoscale systems will develop on
the nose of the deeper moisture and instability, but these are too
small to resolve at this time.

For the southern stream, the positive tilted wave over southern
California slowly treks across into Texas by mid to late week.
There are some longitudinal placement differences seen with the
early 12z guidance compared to the 00z cycle, but differences are
too significant to stray from a general model blend at this time.

The surface pattern will be dominated by an east coast high
pressure for the next couple of days, which is well agreed upon by
the models. A quick moving shortwave across the Northern Plains
and Upper Midwest will drive a low into the Great Lakes by
Wednesday. There is really good agreement with this too in the
both the track and speed.

Finally toward Thursday and Friday, another closed low drops into
the Pacific Northwest. The ECMWF lags the GFS/NAM somewhat but not
significantly and all the deterministic guidance is well within
the ensemble spread and matches fairly close to the means. Overall
for this cycle, there is good support for a general model blend.


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

Taylor