Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1224 AM EDT Wed Jun 05 2019

Valid Jun 05/0000 UTC thru Jun 08/1200 UTC

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

00Z Model Evaluation with Confidence and Preference
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...Overall Pattern Across the CONUS...
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Preference: Blend of the 00Z GFS, 12Z ECMWF
Confidence: Slightly above average

The model preference remains consistent with the preference over
the past couple model cycles -- a blend of the GFS and ECMWF.
Despite some slight run-to-run variability and minor trends, the
GFS and ECMWF have generally been consistent over the past several
model cycles. They also have fairly strong ensemble support.

There are important differences from the other deterministic
models with the low over the southern U.S. and with a trough
moving through the Northwest.

First, with the low evolving over the southern Plains, the 12Z CMC
tends to eject the low much faster than the other deterministic
models, and this does not have much ensemble support. Therefore,
the CMC was generally excluded from the model preference. The 00Z
NAM produces a reasonable forecast with this system and is in line
with the ECMWF and GFS. It could be included in a blend in this
region. Meanwhile, the 12Z UKMET trended slower with the low, and
it parks the mid-upper level low in the Arklatex region into the
weekend. This is plausible, especially with a ridge building over
the top of the low through the Great Lakes. However, it doesn't
have much ensemble support, so for now it is excluded from the
preference.

Second, with the trough moving through the Northwest the 00Z NAM
is much faster than the other deterministic models and most
ensemble members. Therefore, the NAM is excluded from the model
preference for this region.


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

Lamers