773
FXUS01 KWBC 231931
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
330 PM EDT Sun Aug 23 2026

Valid 00Z Mon Aug 24 2026 - 00Z Wed Aug 26 2026

...Dangerous and record-breaking heat continues across the
south-central U.S. into the Southwest...

...Isolated to scattered flash flooding and severe weather threat
across portions of the Southwest and into the Rockies/Plains,
Upper Midwest, and Southeast through Tuesday...


A strong and persistent upper ridge centered over south-central
U.S. and the Southwest will maintain very hot conditions across
the southern tier. Above normal temperatures will continue to have
daily afternoon highs within the upper 90s to 100s, with the
highest values specifically over much of Texas, Oklahoma, eastern
New Mexico, and the Desert Southwest. The combination of little to
no overnight recovery and high humidity (for the Southern Plains)
will allow for heat indices to reach up to 105-115 degrees, which
is where widespread Major to Extreme HeatRisk is forecast.
Furthermore, these abnormal temperatures are expected to break
dozens of high/low daily temperatures through the week. Extreme
Heat Warning and Heat Advisories have been issued across portions
of the Four Corners, Southern Plains, and Lower Mississippi
Valley. The anomalous summer heat wave is expected to persist
through early this week and beyond. See the latest Key Messages
linked at the bottom of the discussion for more information.

North of the ridge, a corridor of enhanced moisture and
instability will extend from the northern Rockies/Plains into the
Midwest and Lower Mississippi Valley. Shortwave energy embedded
within the northwesterly flow will interact with this moisture and
a frontal boundary, resulting in scattered thunderstorms through
Monday. By Tuesday, a system will eject eastward across
south-central Canada and spread rain/thunderstorm chances into the
Upper Midwest. Repeated convection and high rainfall rates may
lead to excessive rainfall and isolated flash flooding, especially
across the Plains into the Lower Mississippi Valley. Additionally,
Storm Prediction Center highlights the potential for severe
thunderstorms, damaging wind gusts, and hail across portions of
the Great Basin and Rockies/Plains through Monday. Further
southwest, monsoonal moisture will continue to bring daily
thunderstorms across the Southwest, Rockies, and Intermountain
West, leading to excessive rainfall/flash flooding concerns the
beginning of this week.

Meanwhile, a surface low and associated frontal boundary affecting
the Northeast will gradually shift eastward, but additional
upper-level energy will support lingering showers and
thunderstorms into Monday across the Lower Great Lakes and
northern New England. Some storms may become locally strong where
sufficient instability develops, which may lead to severe weather
and excessive rainfall concerns. Additionally, the trailing
frontal boundary stretching across the Southeast will bring
chances for severe thunderstorms, damaging winds, and excessive
rainfall on a isolated to scattered basis through Tuesday.


Oudit/Snell


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




$$