378
FXUS01 KWBC 050808
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Sat Sep 05 2026

Valid 12Z Sat Sep 05 2026 - 12Z Mon Sep 07 2026

...Rounds of strong to severe thunderstorms and locally heavy rain
will slowly shift southward across the Midwest, Mid-Atlantic and
into the Southeast during the Labor Day weekend...

...A front moving through the western U.S. could trigger heavy
rain across Utah on Sunday...

...Heat persists across the midsection of the country while cooler
air expands further into the West Coast and the Northeast...

A deepening upper-level low in the vicinity of the Canadian
Maritimes is bringing a cool air mass deeper into the northeastern
U.S. As the leading edge of the cool air mass pushes against the
heat dome across the midsection of the country, a corridor of
strong to severe thunderstorms with scattered heavy rainfall will
be triggered from the Midwest to the Ohio Valley, central/southern
Appalachians, and into the Mid-Atlantic through the first half of
Labor Day weekend. The most active thunderstorms are expected to
be moving through the Midwest to the Ohio Valley this morning,
followed by the central/southern Appalachians and into the
Mid-Atlantic later today and into the evening. A slight risk of
flash flooding is forecast closer to the Mid-Atlantic coast later
today. By Sunday, the front will settle farther southward into the
eastern U.S. This will confine the best chance for the stronger
thunderstorms and heavy rain across the Southeast U.S. Behind the
front, the cool air mass will break the recent spell of heat in
the Northeast and Mid-Atlantic, where high temperatures in the
mid-70s and low 80s can be expected by Sunday. Morning lows
dropping into the 40s and 50s will bring a first taste of fall
across New England for the latter half of the Labor Day weekend.

Meanwhile, a deep upper-level low continues to move further inland
across the northwestern U.S. where scattered showers and embedded
thunderstorms can be expected through the Labor Day weekend.
Farther south, monsoonal moisture will be lifted ahead of a
slow-moving front. It appears that the best chance of showers and
thunderstorms will be later on Sunday across the Great Basin, with
locally heavy rain possible from southern Nevada through Utah,
where WPC highlights a Slight Risk (level 2/4) of excessive
rainfall. Urban areas, as well as dry washes and burn scars will
be most vulnerable to flooding. Temperatures beneath the upper-low
will be cool across the West this weekend as daytime highs dip 10
to 20 degrees below normal. In fact, below freezing morning
temperatures are expected across the higher elevations as far
south as northern California.

Across the northern Plains, a low pressure system is consolidating
ahead of the upper trough moving into the Pacific Northwest.
Rounds of strong thunderstorms are expected to develop across the
northern Plains around the north side of the system. The coverage
and intensity of these thunderstorms and associated heavy rain are
forecast to increase during the latter half of the Labor Day
weekend especially across the northern High Plains as the low
pressure system intensifies.

In contrast, oppressive heat will continue through Labor Day in
the Nation`s Heartland as an upper-level ridge remains anchored
over the midsection of the country. Heat indices of 105 to 110
degrees and record warm overnight temperatures will be widespread
across the Central/Southern Plains States and Mississippi Valley
this weekend. See WPC`s Key Messages for more information on the
heat, limit afternoon outdoor activity if possible, and stay
hydrated regardless of your Labor Day plans.


Kong/Asherman


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

Extreme Heat Key Messages available at:
https://www.wpc.ncep.noaa.gov/key_messages/LatestKeyMessage_1.png




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