Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
249 PM EDT Tue Jul 14 2020
Valid Jul 14/1200 UTC thru Jul 18/0000 UTC
...See NOUS42 KWNO (ADMSDM) for the status of the upper air
ingest...
12Z Model Evaluation with Final Preferences/Confidence
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...Mid-level shortwave troughing over the northeastern quarter of
the U.S. Monday to Wednesday...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: General model blend
Confidence: Average
The models show similarly with this system during the time frame
that it has impacts across the Northeast U.S.. A general model
blend should maintain the overall pattern while dampening any
minor differences.
...Longwave trough axis moving through the north-central U.S.
through Wednesday with accompanying surface cold front...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: 12Z GFS/ECMWF/UKMET blend
Confidence: Average
As a large closed low and associated longwave trough axis track
eastward across southern Canada through the rest of the week, a
corresponding cold front will move into the Great Lakes and Great
Plains. The 14/12Z NCEP and non-NCEP model mass fields aloft
maintaining a high degree of continuity. Still think that 14/12Z
GFS/ECMWF/UKMET are in good enough agreement to each other to
prefer a blend of them.
...Cut off low west of California by Thursday morning and
progressive trough crossing the Pacific Northwest...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: non 14/00Z UKMET blend
Confidence: Average
The latest models continue to show good agreement with a 700-500
mb low closing off by mid-week over the western U.S. and
retrograding offshore of California by late in the day Wednesday.
There is also good agreement, albeit minor amplitude differences,
with a progressive mid-level trough axis into the Northwest on
Thursday. A general model blend represents both systems along the
West Coast well.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
This product will terminate August 15, 2020:
www.weather.gov/media/notification/pdf2/scn20-58pmdhmd_termination.
pdf
Bann