Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
345 AM EDT Thu Sep 28 2023

Valid 12Z Thu Sep 28 2023 - 12Z Sat Sep 30 2023

...Heavy rain and flash flooding possible across parts of the Northeast on
Friday...

...Wet weather pattern continues throughout Florida and the Northwest...

...Well above average temperatures expected across the central Plains and
parts of the Midwest...

Damp and dreary weather is forecast to return to the Northeast by this
evening and linger through Friday as an area of low pressure develops
offshore. This low pressure system will help a stream elevated atmospheric
moisture content from the Atlantic Ocean towards the northern Mid-Atlantic
States. After light showers and drizzle overspread much of the region
tonight, pockets of heavier rain may develop by Friday morning between New
Jersey and western Connecticut. A localized area of enhanced convergence
may provide enough lift in the atmosphere to support continuing downpours
through much of the day on Friday. Additionally, any instances of
potentially heavy rain are not anticipated to move quickly and could
linger over the same region for hours. As a result, flash flooding is
possible and prompted a Slight Risk (level 2/4) of Excessive Rainfall to
be issued from southern New Jersey to southern Connecticut, including the
Lower Hudson Valley and Long Island. Urban locations, which are prevalent
in this area, will be most prone to rapid water rises and flooding
concerns. Residents and visitors are advised to remain weather aware and
never drive through flooded roadways.

Farther south along a slow moving frontal boundary draped across the
Florida Peninsula, daily shower and thunderstorm chances are forecast to
continue through at least the beginning of the weekend. The main weather
hazards associated with the developing thunderstorms will be frequent
lighting and heavy rain. Intense rainfall rates could lead to localized
flooding concerns, mainly over urban corridors, which is highlighted by a
Marginal Risk (level 1/4) of Excessive Rainfall.

Pockets of unsettled weather are also in the forecast over the next few
days over the Ohio and Tennessee valleys, Upper Midwest, Northwest, and
southern High Plains. Starting in the Northwest, a deep upper trough
diving into the West Coast by Saturday will allow for showers to become
more widespread after days of scattered rain chances. Cool temperatures
and precipitation should span from central California through the
Intermountain West and northern Great Basin. The highest elevations of the
Sierra Nevada, northern Cascades, and northwest Montana could see
accumulating snowfall as upper level temperatures cool to around freezing.
Meanwhile, one more day of wet weather conditions is anticipated over the
Ohio and Tennessee valleys today as a weakening low pressure system and
stationary front linger over the region. A few storms could overlap and
contain heavy rainfall, which may lead to localized flash flooding for
Kentucky and Middle Tennessee. Localized flooding concerns are also in the
forecast on Friday across central/northern Minnesota and Saturday over
eastern New Mexico and Wet Texas as robust thunderstorms cross these parts
of the country.

Outside of the cooler conditions located throughout the West,
Mid-Atlantic, and Northeast, a majority of the Nation will see well above
average temperatures build into the beginning of the weekend. The warmest
temperature anomalies are expected to be found across the central Plains
and parts of Midwest. High temperatures here are forecast to reach into
the 80s and low 90s, which equates to around 20 degrees above climatology
for late-September. Afternoon highs into the 80s and 90s will also stretch
into the middle and lower Mississippi valleys, as well as the Southern
Plains.

Snell

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