Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
358 AM EDT Tue Sep 08 2026

Valid 12Z Tue Sep 08 2026 - 12Z Thu Sep 10 2026

...Strong to severe thunderstorms with heavy rainfall shift southeastward
into the Midwest today, stretching from the Midwest to interior New
England by Wednesday night...

...Modest relief from the heat across the midsection of the country by
late Wednesday as some heat returns to the Mid-Atlantic....

As a large high-pressure system brings fine and cool weather across much
of the eastern U.S., a frontal system trailing from an intensifying
low-pressure system across southern Canada has triggered strong to severe
thunderstorms scattered across the upper Midwest to the central Plains
early this morning. The southern portion of the front will begin to lose
momentum, allowing showers and thunderstorms to develop and move more
slowly across the north-central Plains, gradually advancing across the
Upper Midwest and reaching the Great Lakes by tonight. WPC continues to
highlight a slight risk of excessive rainfall across Iowa as SPC maintains
a slight risk of severe thunderstorms for the same general area today into
early Wednesday. By Wednesday, showers and thunderstorms are expected to
stretch from the central Plains, through the Midwest and Ohio Valley,
reaching into interior New England by Wednesday night as the front
advances gradually to the south and east. WPC now highlights a slight risk
of excessive rainfall across central Missouri into adjacent areas for
Wednesday into early Thursday.

As the high pressure system continues to expand southward into the eastern
U.S. against the heat dome anchored over the country's midsection, a
frontal boundary will remain stalled across the eastern Gulf Coast and the
Florida Peninsula. This pattern will allow scattered showers and embedded
thunderstorms to linger across the eastern Gulf Coast region, including
the Sunshine State, through the next few days. Meanwhile, much of the
Northeast and Mid-Atlantic will begin a gradual warming trend towards more
seasonable temperatures as the cool airmass begins to moderate. The
exception will be across northern New England where a reinforcing surge of
cold air is forecast to drop temperatures into the 30s by Wednesday
morning.

Temperatures across the western U.S. will follow a similar warming trend
starting today 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 in store 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 today into Wednesday from the
central Plains to the mid-Mississippi Valley. Some heat is expected to
return to the Mid-Atlantic as highs climb back into the upper 80s.
Elsewhere, some late-day monsoonal showers and storms will maintain a
marginal risk of flash flooding mainly across Arizona and New Mexico
through the next couple of days, possibly extending into interior
California on Wednesday.

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/basicwx/basicwx_ndfd.php