Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
312 AM EDT Mon Mar 18 2019
Valid Mar 18/0000 UTC thru Mar 21/1200 UTC
...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...
00Z Model Evaluation Including Preferences and Confidence
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...Overall Pattern Across the CONUS...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: General Blend with a lean to 00Z GFS, 12Z CMC
Confidence: Average
The greatest model differences over the next few days are related
to a shortwave trough digging through Saskatchewan this morning,
and pushing into the Plains through mid-week. Outside of that,
model agreement is fairly good and a general blend is the overall
recommendation.
Compared to the model consensus, the 12Z ECMWF was most difference
with the aforementioned shortwave. Most models gradually swing the
wave southeast, reaching the Mid South by Thursday. The ECMWF,
however, digs the wave further west, and eventually extends the
lobe of vorticity west toward the Great Basin via shearing and
deformation on the south side of an upper level high over Montana.
Some of this vorticity eventually gets pulled into the north side
of a trough pushing onto the West Coast on Thursday. This is
considerably different than the other available models.
There is also some continued spread with the speed and timing of
the wave as it swings through the Central US. GEFS members are the
fastest along with the 12Z UKMET, while the 00Z NAM/GFS and 12Z
CMC are slightly slower, but still faster than the ECMWF. The
preference is to lean toward the GFS and CMC with respect to this
wave, and also into the Intermountain West on Day 3 (Wednesday
afternoon and night). Otherwise, a general model blend is
preferred given fairly good agreement.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Lamers