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Model Diagnostics Discussion
(Latest Discussion - Issued 0713Z Nov 20, 2018)
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
Abbreviations and acronyms used in this product
Geographic Boundaries -  Map 1: Color  Black/White       Map 2: Color  Black/White

Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
213 AM EST Tue Nov 20 2018

Valid Nov 20/0000 UTC thru Nov 23/1200 UTC

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

00Z Model Evaluation...with Preferences and Confidence

...Overall Pattern Across the CONUS...
Preference: 00z GFS/NAM/ECMWF
Confidence: Slightly above average

07z update: No significant changes noted with the 00z
ECMWF/CMC/UKMET compared to the rest of the deterministic
guidance. As such, a blend of the 00z GFS/NAM/ECMWF is preferred.

---previous discussion---
Quasi-zonal split flow across the CONUS will gradually transition
as a western ridge moves east with more downstream troughing over
the eastern US. By the end of the forecast period, troughing will
move into the western US, bringing several systems and

An area of low pressure currently over the mid-Atlantic will
deepen some Tuesday and Tuesday night off the New England coast
while another shortwave trough and associated low pressure skirts
through the Great Lakes region Tuesday night into Wednesday. An
anomalously strong high pressure in its wake will bring near
record cold to the Northeast for Thanksgiving.

The models have clustered together in the past 24 hours and show
fairly good agreement in the large scale synoptic pattern. Some
very minor differences are noted with the southwest US open wave
as it moves into Texas by Wednesday night, where the CMC/UKMET are
still a bit slower and further south compared to the GFS/NAM/ECMWF
solutions. For the western trough coming onshore Wednesday night,
the GFS is a touch faster compared to the rest of the models. Its
associated surface low is also a bit deeper (and faster) compared
to the ECMWF.

Overall, given the relatively good agreement across the CONUS, a
blend of the 00z GFS/NAM with the 12z ECMWF is preferred at this

Model trends at
500 mb forecasts at