Prognostic Meteorological Discussion
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951
FXUS01 KWBC 080804
PMDSPD

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/key_messages/LatestKeyMessage_1.png




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