Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
333 PM EDT Fri Jun 14 2019

Valid Jun 14/1200 UTC thru Jun 18/0000 UTC

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

12Z Final Model Evaluation...with Confidence and Preferences
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...Overall Analysis Across the CONUS...
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Preference: Non-UKMET Blend
            Greater weight 12Z ECMWF, least weight 12Z GFS/NAM
Confidence: Average

---19Z UPDATE---
No significant changes to the previous preference. The UKMET
continues to show higher heights through the Central U.S.;
otherwise a blend weighted toward the ECMWF is preferred.

---PREVIOUS DISCUSSION---
Models are generally in agreement on the synoptic pattern through
the weekend, with broad troughing from the Northern Plains into
the Northeast, a Rex block pattern of sorts across western North
America, and weak flow with some embedded waves from the Southern
Plains into the Southeast.

The greatest difference from a deterministic model is with the 00Z
UKMET which shows considerably more ridging aloft and higher
heights across the central U.S. by Sunday night (after 16.18Z).
500mb isoheights from the UKMET fall outside the envelope of all
ECMWF and NAEFS ensemble members in some areas. Given the lack of
ensemble support, this model is excluded from the preference.

Otherwise, the remaining models are reasonably similar in many
aspects. The primary difference is with slightly lower heights
aloft on the 12Z NAM and GFS upstream from a large upper level low
in Quebec, putting a some stronger shortwaves through the Upper
Mississippi Valley. The preference is to lean toward the ECMWF and
CMC in this respect with slightly less weight on the GFS and NAM.
Given the natural ridge expected upstream of such a strong upper
level low (and positive height trends in central Canada overall),
this may weaken any shortwaves embedded in the flow over the
Canadian Prairies and Northern Plains this weekend.


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

Lamers