Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
1222 PM EDT Sun Aug 25 2019

Valid Aug 25/1200 UTC thru Aug 29/0000 UTC

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

12Z Model Evaluation with Preferences and Forecast Confidence
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

...Overall Pattern Across the CONUS...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: General model blend
Confidence: Slightly above average

The deterministic models are in fairly good agreement, despite
some variation in the amplitude of several waves across the CONUS
over the next few days. All of the available deterministic model
height fields aloft are contained well within the envelope of
ensemble spread. This has led to relatively similar QPF fields as
well. For instance, on Day 3 (28.00Z to 29.00Z) the major axes of
heavy rainfall over the south-central U.S. and in the Mid Atlantic
is generally within 100mi of each other despite some variety in
rainfall magnitude.

Therefore, forecast confidence is slightly above average with some
lingering uncertainty over details due to convective evolution. A
general model blend is preferred, as each of the available models
has some ensemble support and thus could represent a reasonable
variation on the placement of rainfall. The 00Z ECMWF did place
some very localized QPF maxima in excess of 5 inches along the Mid
Atlantic coast on Day 3, which does not have substantial support
from other models. Therefore, the ECMWF may receive slightly less
weight on Day 3 in that region.


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

Lamers