Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
359 PM EDT Tue Oct 18 2022

Valid 00Z Wed Oct 19 2022 - 00Z Fri Oct 21 2022

...Widespread record-breaking cold early Wednesday morning across the
Mid/Lower Mississippi Valley, Central/Southern Appalachians and
Southeast...

...Freeze Warnings and Frost Advisories in effect for the Southern Plains,
Ohio and Tennessee Valleys, Southeast, and Mid-Atlantic...

...Scattered Flash Flooding possible for portions of Maine through
tonight...

A low pressure system has been gradually moving across the Great Lakes
region and is responsible for snowfall early this week. The system is
slowly moving northwards and will continue to do so over the next couple
days. Light snow and mixed precipitation will continue to be possible near
the Great Lakes over through Wednesday, then chances will diminish on
Thursday.

There are two trailing cold fronts associated with the low pressure system
over the Great Lakes region that are responsible to pushing colder air
into the eastern half of the US. At 2PM Tuesday afternoon, the first front
extended from Maine offshore into the Atlantic and across Central Florida.
The second front extended from New York to North Carolina. Heavy
precipitation ahead of and along the cold front across Maine could lead to
scattered flash flooding through tonight, especially in urban areas and
areas with poor drainage. There is a Slight Risk of Excessive Rainfall
(level 2/4) in effect for central and eastern Maine through early
Wednesday morning.

Strong high pressure sliding south behind the cold fronts will continue to
build across the Central US tonight, bringing bitter cold air down from
Canada. Low temperatures late tonight/early Wednesday morning are forecast
to be in the 20s and 30s (20-25 degrees below normal) across most of the
Central and Eastern US, and some locations may drop down into the teens.
Widespread minimum temperature records are expected to be set across the
Mid/Lower Mississippi Valley, Central/Southern Appalachians, and
Southeast. A large swath of Freeze Warnings and Frost Advisories have been
issued for the Southern Plains, Ohio and Tennessee Valleys, Southeast, and
Mid-Atlantic.

The cold front will push east of the US on Wednesday, and the stationary
frontal boundary banked up against the Rocky Mountains will push east as a
warm front Wednesday through Friday as a low pressure system moves across
southern Canada. Temperatures in the Central and Eastern US will gradually
increase through the end of the work week, reaching slightly above normal
values by this weekend. While the east warms up, temperatures will cool
over the Pacific Northwest late this week as a cold front begins to move
southeast across the region.


Dolan

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