Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1123 AM EST Fri Dec 21 2018

Valid Dec 21/1200 UTC thru Dec 25/0000 UTC

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

12Z Model Evaluation...with Preferences and Confidence
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: General model blend, weighted increasingly to
            00Z ECMWF, 00Z ECMWF ENS after 23/12Z
Confidence: Average

Models show fairly good similarity with the synoptic pattern and
overall forecast for the next couple days, with the greatest
differences arriving with the trough in the Northwest early next
week. The preference is to utilize a general model blend for the
first couple days of the forecast, as there is limited model
spread.

By Monday, the preference becomes increasingly weighted toward the
ECMWF and ECMWF Ensemble Mean. A significant number of ECMWF
ensemble members, and some CMC and GEFS ensemble members are more
amplified with the approaching trough than the non-ECMWF
deterministic models. Given the stronger ensemble support for the
ECMWF, the forecast is weighted increasingly in that direction
(and the ECMWF Ensemble Mean), while still incorporating a certain
portion of the other deterministic models.


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

Lamers