647
FXUS01 KWBC 220521
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
119 AM EDT Sat Aug 22 2026

Valid 12Z Sat Aug 22 2026 - 12Z Mon Aug 24 2026

...Flash flooding and severe weather threat across portions of
eastern U.S. on Saturday...

...Flash flooding and severe weather threat across portions of
Rockies/Plains into the Southwest through the weekend...

...Dangerous heat continues across south-central U.S. into the
Southwest through the weekend...


A amplified pattern with a deepening trough over eastern U.S. and
persistent ridging over the southern Plains/Southwest will bring
unsettled conditions across the Rockies/Plains into eastern U.S.
into early next week. At the surface, the low over the Great
Lakes/Ohio Valley will continue to strengthen, while frontal
boundaries begin to merge. The slow moving boundary will drape
across the Ohio Valley/Mid-Atlantic, into the Southeast and
southern Plains by Saturday. Increasing cyclonic flow, upper-level
forcing, and sufficient moisture will maintain multiple rounds of
showers and thunderstorms along the boundary, with locally heavy
rainfall possible across portions of the Great Lakes,
Mid-Atlantic/Carolinas into the Northeast. By Sunday, the system
will continue to move eastward, with cyclogenesis north of the
Great Lakes, supporting additional showers for portions of the
Northeast. Additionally, Storm Prediction Center highlights a
severe thunderstorm threat capable of producing severe hail and
wind across portions of southern Plains and Ohio Valley/Great
Lakes/Mid-Atlantic for Saturday, while the threat is confined to
the Northeast by Sunday.

Further west, the stationary frontal boundary will continue to
stretch across the Rockies/Plains into the Four Corners. The
combination of the shortwave disturbances, slow moving frontal
boundary, and moisture influx can lead to showers and
thunderstorms. These systems may be capable of producing excessive
rainfall/flash flooding, lightning, severe hail and damaging winds
across portions of the Rockies/Plains into the Southwest through
the weekend.

The southern tier will remain dominated by the upper-level ridging
centered over the Southwest. This will maintain above normal
temperatures into next week. The dangerous heat will build across
south-central U.S. and Southwest with daytime highs of 100-110
degrees across the Southern Plains into the Southwest, with
numerous record breaking highs. 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.


Oudit


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




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