436
FXUS01 KWBC 212001
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Fri Aug 21 2026

Valid 00Z Sat Aug 22 2026 - 00Z Mon Aug 24 2026

...Broad area of thunderstorms maintain a scattered severe weather
and flash flood threat across the Central and Eastern U.S.;
monsoon activity continues over the West...

...Dangerous heat persists in the South while building into the
Southwest through the weekend...

Unsettled summertime weather will continue through the weekend
from the Plains states eastward as an amplifying frontal system
near the Upper Great Lakes merges with a stalled frontal boundary
draped across the Mid-South. The leading boundary in the Mid-South
will support multiple rounds of thunderstorms capable of scattered
flash flooding this afternoon and tomorrow across portions of the
Mid-Atlantic. Severe weather is also a concern across the
Southeast today, where the Storm Prediction Center has highlighted
a Slight Risk for damaging wind gusts. Meanwhile, the Great Lakes
boundary will sink southward today, supporting a separate corridor
of severe weather from northern Illinois to western Nebraska. By
tomorrow, the boundaries will begin to merge together, ushering in
additional heavy rainfall across the Eastern Seaboard with pockets
of isolated severe also possible form the Midwest to the Northern
Rockies. Across the southwest, monsoonal moisture will remain
concentrated across the Four Corners and Southern Rockies.
Afternoon heating combined with terrain-driven circulations will
initiate scattered thunderstorms through the weekend, leading to
locally heavy rainfall from slow-moving storms.

Meanwhile, dangerous heat continues across the south-central U.S.
and the Southwest through the weekend as an amplified upper-ridge
continues to support above normal temperatures. Numerous daily
record highs are expected, with daytime highs of 100-110 degrees
across the Southern Plains into the Southwest. With little to no
overnight relief, as minimum temperatures will remain warm, and
high humidity, heat indices may reach 105-115 degrees. Therefore,
expect widespread Major to Extreme HeatRisk through the weekend.
Refer to Key Messages issued by WPC for additional information on
this event.


Asherman/Oudit


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




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