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Model Diagnostics Discussion
(Caution: Version displayed is not the latest version. - Issued 0800Z Feb 20, 2019)
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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
300 AM EST Wed Feb 20 2019

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

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

00Z Model Evaluation...with Final Preferences and Confidence

...Overall Pattern Across the CONUS...
Preference: General model blend
Confidence: Above average

08z update: With the rest of the 00z guidance now in, there
continues to be above average forecast confidence with the models
through the next 3 days across the CONUS. As such, the WPC
preference for a general model blend remains the same.

---previous discussion---
Despite the active weather pattern in the next 3 days, there is
above average model agreement in the large scale pattern across
the CONUS. Current shortwave trough moving through the Southwest
US will lift into the Plains and Great Lakes region over the next
24 hours and all the operational models seem to have a good handle
on that feature's evolution. The 00z NAM continues to show some
stronger amplification and also takes the surface low a bit
further northwest compared to the rest of the models, but all of
them are within the ensemble spread. As that low moves over the
Great Lakes, a coastal low is forecast to develop  off the
Mid-Atlantic. The NAM has this forming the earliest, near the
NC/VA border, while the GFS/ECMWF are about 6 hours later and
further north.

Then with the next shortwave trough digging into the southwest US
and then ejecting out into Texas, there again looks to be fairly
good agreement in the synoptic pattern. There seems to be minor
differences in the where the low forms in the lee of the Rockies
at the end of day 3.

Overall, with the above average forecast confidence, the
preference will remain the same for a general model blend.

Model trends at
500 mb forecasts at