Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
355 PM EDT Fri Sep 22 2017

Valid 00Z Sat Sep 23 2017 - 00Z Mon Sep 25 2017

...Below average temperatures in the western half of the U.S. with above
average temperatures in the eastern half...

...Heavy rain and thunderstorms in the central U.S. along a slow-moving
cold front...

A deep upper-level trough is in place across the western U.S., while an
upper-level ridge is present over the northeastern U.S. At the surface, a
cold front is located on the eastern edge of the trough, stretching from
the Northern Plains into the Southwest. This setup is leading to a strong
temperature contrast across the U.S. The West is expected to be much
colder than average over the weekend, with temperatures forecast to be up
to 30 degrees below average in Wyoming in particular. On the other hand,
the eastern U.S. will have widespread high temperatures in the upper 80s
and lower 90s. This is 20-30 degrees above average in the Upper Midwest
and the Northeast. The trough will shift gradually eastward over the next
couple of days, allowing the cold front to move slowly with it, stalling
by Sunday. Along the front, rain and thunderstorms are likely for the
Plains and into the Upper Midwest through the weekend. Some storms are
forecast to contain heavy rainfall, leading to a slight chance of flash
flooding. Today and tonight there is a slight risk of severe weather for
portions of the Upper Midwest as well. Behind the front in the cold air,
snow is expected to continue for the Northern and Central Rockies and in
the Central Great Basin.

Post-Tropical Cyclone Jose will continue to weaken off the coast of the
Northeast, and light rain and wind gusts occurring in New England will
subside as it weakens. High surf along the East Coast and hazardous marine
conditions could continue through the weekend, however. See the National
Hurricane Center's website for more information on Jose.

Elsewhere, warm temperatures and plenty of moisture will help form
scattered thunderstorms along the Gulf Coast and in the Southeast through
the weekend.


Tate


Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php