Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
329 PM EDT Mon Sep 18 2023

Valid 00Z Tue Sep 19 2023 - 00Z Thu Sep 21 2023

...Heavy rainfall and localized flash flooding possible for New England
through Monday night...

...Heavy rain and severe storm chances return to parts of the Southern
Plains on Tuesday...

...Above average heat forecast for the Central U.S. through mid-week...

A low pressure system tracking north along the New England coast will
continue rain chances through tonight for much of the Northeast. With
warm, moist air in place over the region, periods of heavy rainfall will
be possible, and much of Maine and parts of Vermont and New Hampshire
could receive an additional 1-2 inches of rain overnight tonight into
Tuesday. Isolated to scattered instances of flash flooding will be
possible, and there is a Slight Risk of Excessive Rainfall (level 2/4) for
areas from Rhode Island to Central Maine. Areas that received heavy
rainfall from Lee over the weekend may be particularly sensitive to
flooding because the soils are already saturated. The low pressure system
will push into Canada on Tuesday and rain chances will gradually decrease.

Wet weather is also forecast to impact parts of the Florida Peninsula and
Southern Plains Tuesday and Wednesday. A slow moving frontal boundary will
remain draped across Central and South Florida into the northern Gulf of
Mexico and extend back across the Southern Plains. Daily rounds of showers
and thunderstorms are forecast for Florida, and locally heavy rainfall and
isolated flash flooding may be possible, mainly in urban areas and areas
with poor drainage. In the Southern Plains, an upper level shortwave will
move over the area Tuesday into Tuesday night, which will provide support
for the development of stronger thunderstorms. Scattered severe
thunderstorms will be possible in parts of Oklahoma and Texas with large
hail and damaging winds being the primary hazards. The Storm Prediction
Center has issued a Slight Risk of Severe Thunderstorms (level 2/5) for
this area. Locally heavy rainfall may also produce isolated to scattered
instances of flash flooding, and there is a Slight Risk of Excessive
Rainfall (level 2/4) in effect for parts of Oklahoma.

Elsewhere, scattered showers, thunderstorms, and high elevation snow will
be possible across the Intermountain West Tuesday and Wednesday along a
nearly stationary frontal boundary. Precipitation chances will increase
across the West Wednesday into Thursday as a deep upper level low moves
over the region. Shower and thunderstorm chances will expand into the
Central U.S. Thursday as the upper low pushes east.

Above average heat is forecast to persist through mid-week for much of the
Central U.S. where high temperatures will reach 10-20 degrees above
normal. High temperatures will range from the low-to-mid 80s to the mid
90s across the region. Warmth will gradually spread east, reaching the
Great Lakes region by Wednesday. In the West, temperatures are expected to
drop to 10-20 degrees below average later this week after the upper low
moves in. Cooler temperatures will develop in the Pacific Northwest by
Wednesday, then expand into the Southwest and Intermountain West Thursday.
Temperatures in the East will remain near seasonable values for this time
of year.


Dolan

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