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/basicwx/basicwx_ndfd.php