Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
147 PM EDT Fri Aug 23 2019

Valid Aug 23/1200 UTC thru Aug 27/0000 UTC

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

12Z Initial Model Evaluation Including Preferences and Forecast
Confidence
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...Overall Pattern Across the CONUS...
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Preference: 00Z ECMWF/UKMET
Confidence: Average

Strong model agreement with the synoptic flow across the CONUS
begins to diverge on Sunday, particularly from the 12Z GFS which
is more amplified and progressive with the trough moving southeast
from southwestern Canada than the rest of current guidance and
farther east with the trailing low over the Northeast CONUS Sunday
to the Canadian Maritimes through Monday. Day 2 QPF remains in
excellent agreement among current guidance with an arc from the
northern to central Great Plains to northern FL. However,
differences among guidance with the system moving north from
southern FL remain and agreement is still seen in the UKMET/ECMWF
which has been preferred for the past few days. The stronger and
more progressive storm in these two models increases QPF along
western NC on Day 2 which is placed farther north in a trough in
the 12Z NAM/GFS while the 00Z CMC remains very weak. Therefore,
the preference for the entire CONUS is now the 00Z UKMET/ECMWF.

As for TS Ivo in the EPAC, there is close track agreement with
latest consensus and the 12Z NHC track through Sunday as it
weakens with similar solutions in the models with moisture
advection into the Desert SW through Monday.

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

Jackson