Prognostic Meteorological Discussion
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950
FXUS01 KWBC 071928
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
327 PM EDT Mon Sep 07 2026

Valid 00Z Tue Sep 08 2026 - 00Z Thu Sep 10 2026

...Severe thunderstorms and heavy rainfall expected across the
Northern Rockies and the Northern Plains today, spreading
southeastward this week...

...Modest relief from the heat across the midsection of the
country late Wednesday; cooler air begins to moderate across the
Northeast and Western U.S....

...Scattered thunderstorms linger across the Southeast...

As a large high-pressure system brings fine and cool weather
across the Great Lakes and the Northeast this Labor Day, a
low-pressure system is spreading unsettled weather into the
northern Rockies and the northern Plains. This is in response to a
deep upper-level low getting ready to eject out of the northern
Rockies toward southern Canada. Strong dynamics associated with
this weather system will bring heavy rainfall and scattered severe
thunderstorms across the Northern Rockies to the Northern Plains
as today progresses. The low-pressure system is forecast to
intensify and move into the southern prairies of Canada by
tonight, but the potent cold front trailing from the low center
will bring a round of strong to severe thunderstorms as the front
sweeps through the northern Plains today, reaching into the upper
Midwest tonight. By Tuesday, the southern portion of the front
will lose some momentum, allowing showers and thunderstorms to
develop over the north-central Plains and advance gradually into
the Upper Midwest by Wednesday morning. A Slight Risk of excessive
rainfall remains in effect across Iowa Tuesday to early Wednesday.

As the high pressure system continues to expand southward into the
Eastern U.S. and encounters the heat dome anchored over the
country`s midsection, the frontal boundary will eventually stall
before reaching the Gulf Coast. This pattern will allow scattered
thunderstorms to linger across the Southeast, including the
Sunshine State, through the next few days. Behind the front, much
of the Northeast and Mid-Atlantic will begin a gradual warming
trend towards more seasonable temperatures as the cool airmass
begins to moderate, with the exception of northern Maine as
reinforcing cold air arrives Wednesday morning.

Temperatures across the Western U.S. will follow a similar warming
trend beginning tomorrow as mid-level heights rise with the
departure of the lingering upper-low. East of the Rockies, some
much needed relief from the oppressive heat is expected late
Wednesday with the arrival of the trailing cold front from the
Canadian cyclone. Until then, however, daytime highs in the
upper-90s and triple digits combined with record warm temperatures
will maintain dangerous heat for the next 24-48 hours over the
Plains and Middle Mississippi Valley.

Asherman/Kong


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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