814
FXUS01 KWBC 240755
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
354 AM EDT Sun Aug 24 2025

Valid 12Z Sun Aug 24 2025 - 12Z Tue Aug 26 2025

...Excessive rainfall concerns expand across parts of the Four
Corners, Great Basin, Sierra Nevada and Central/Southern Plains
amid resurgent monsoon activity...

...Heat wave begins to diminish in Southwest on Monday and
continues in Northwest...


An upper ridge centered over the Four Corners region with
shortwave energy rotating around it will be the focus for heat and
excessive rainfall concerns over the next few days. Anomalous
moisture will continue to surge into the Western U.S. today.
Upslope enhancement of moisture over parts of the Sierra may
produce flash flooding, particularly over the central Sierra,
where a slight risk (at least 15% chance) of excessive rainfall
leading to flash flooding is in effect. Another slight risk area
is over portions of southern Utah, where any storms that produce
heavy rainfall could produce instances of flash flooding in slot
canyons. A high end slight risk (at least 25% chance) of excessive
rainfall is in effect from parts of eastern Colorado into the
Texas/Oklahoma panhandles and western Kansas, where a complex of
thunderstorms moving south could encounter increased instability
leading to enhanced rain rates this afternoon/evening. The slight
risk areas shift into portions of central/southern Colorado,
northeastern New Mexico and Oklahoma, southern Kansas and western
Arkansas on Monday.

An upper trough, coming from the East Pacific, will begin to
degrade the upper ridge centered over the Southwest early this
week. Stormy monsoon conditions in the Southwest will likely
alleviate the heat wave in the Southwest beginning on Monday,
while continued southerly flow and clearer skies should allow for
an expansion of the heatwave in the Northwest through early this
week. Extreme heat warnings and watches remain in effect across
portions of the Desert Southwest, southern California, Washington,
Oregon and northern California. For many areas there will be
little nighttime relief from the extreme heat, with overnight lows
remaining well above normal. Numerous nighttime temperature
records are likely. Extreme heat is dangerous even at night when
temperatures don`t cool down. Without A/C or cooling, the body
can`t recover, increasing the risk of heat illness.

Elsewhere, a cool and dry continental airmass associated with
surface high pressure will descend on the Central U.S. from Canada
over the next few days. High temperatures in the 60s and 70s will
be 15-30 degrees below average from the Great Plains to the
Midwest. Some isolated record low maximum temperatures may be
realized on Monday and Tuesday. These cool and dry conditions
spread into the Eastern U.S. later this week.


Kebede


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