Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
343 PM EDT Thu Aug 22 2019

Valid Aug 22/1200 UTC thru Aug 26/0000 UTC

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

12Z Final Model Evaluation Including Preferences and Forecast
Confidence
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...Overall Pattern Across the CONUS...
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Preference: General Model blend
Exceptions: ECMWF/UKMET blend from FL to off Carolinas Days 2/3
Confidence: Slightly above average

...19Z Update...
12Z guidance is all similar in the precip arc down the northern
and central Great Plains, across the southeast and up the southern
Mid-Atlantic coast and a general model blend remains the
recommendation. The 12Z ECMWF and UKMET remain the most developed
with the trough moving from south FL to off the Carolina Coast
tonight through Sunday and remain the preference there.

The 12Z consensus on TS Ivo is closest to the 12Z GFS by 26/00Z
which is similar to the 15Z NHC track.

...Previous Discussion...
Overall very good agreement on progression of the synoptic flow
pattern across North America through Sunday including the trough
spreading east from the Gulf of Alaska across the northwest CONUS
and to the northern Plains, the progression of the mid-level ridge
from the Great Plains to eastern Canada, and low/trough
progression over eastern Canada and lingering trough over the
Northeast CONUS. Overall good agreement on placement in the QPF
arc that is meridional up the Great Plains then around the
southeast to the southern Mid-Atlantic that wholly shifts east
from Day 2 to 3.

Three tropical concerns also are in play over southern FL, the
west-central Gulf Coast, and TS Ivo in the eastern Pacific. Will
continue to prefer the ECMWF/UKMET which remain in good agreement
for surface low develop over south-central portions of the FL
peninsula with the highest QPF off the southeast FL coast on Day 2
and near the eastern NC coast on Day 3. A lingering tropically
sourced trough over the western Gulf of Mexico brings locally
heavy rains to the coast of far eastern TX/southern LA for both
Days 2/3. And in the Pacific the 15Z NHC forecast for TS Ivo is
closest to the GFS track.


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

Jackson