Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
432 AM EDT Tue May 28 2019

Valid May 28/0000 UTC thru May 31/1200 UTC

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

00Z Model Evaluation Including Preferences and Forecast
Confidence...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

...Overall CONUS Overview...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: General model blend day 1/2; ECMWF/UKMET blend day 3
Confidence: Average

Update: No significant changes to the model preference now that
the rest of the 00z guidance is now available.

---previous discussion---
Current closed low over the interior Rockies will move into the
central Plains and open up by Wednesday while the subtropical
ridge anchored over the southeast US gets shunted further south.
The closed low will phase with a strong shortwave moving over the
James Bay to eventually carve out troughing over the Northeast US
and New England by the end of the forecast period. Baggy
troughiness will likely continue as well over the western US.

In general, the pattern is well advertised by the latest 00z
guidance in comparison with the earlier 12z guidance, through
about 48 hours or 30.00z. Beyond that time period, particularly
with how the northeast US troughing evolves, there are some bigger
model differences. An area of low pressure moving from the mid-MS
River Valley into the Ohio Valley will eventually redevelop off
the coast and deepen. The GFS is on the faster side of the model
spread while the UKMET is on the slower end. There are also
timing/phasing issues by the end of the forecast period as the
system becomes wrapped up in the larger troughing over the
northeast US. This leads to some wide QPF solutions, with some
models painting the highest over the mid-Atlantic then all the way
to northern New England. A consensus approach would favor a
solution similar to the ECMWF or UKMET, which seems plausible for
day 3. As such, a general model blend can be applied for day 1/2,
then a ECMWF/UKMET is favored for day 3.


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

Taylor