546 
FXUS01 KWBC 230603
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
202 AM EDT Wed Sep 23 2026

Valid 12Z Wed Sep 23 2026 - 12Z Fri Sep 25 2026

...Significant Heavy Rainfall/Flooding Threat across New Mexico
and the Southern High Plains through Thursday...

...Heavy Rainfall/Flooding Threat across portions of the
Ohio/Tennessee Valley, Mid-Atlantic, and portions of the Southeast
through Wednesday...


The well-defined shortwave energy will continue to lift northward
into New Mexico, while strengthening upper-level forcing
overspreads across parts of the Four Corners and southern/central
Plains. The combination of deep moisture, instability and
upper-level forcing, widespread showers and thunderstorms may
produce high-rainfall rates that may lead to flash flooding,
especially across sensitive terrain, burns scars, and urban areas.
Therefore, WPC continues to highlight a Moderate Risk (at least
40% chance) of excessive rainfall across portions of New Mexico, a
Slight Risk (at least 15% chance) expanding into West Texas,
Arizona, and Colorado, and a Marginal Risk (at least 5% chance)
across portions of the Four Corners into central Plains. Further
north, a slow-moving boundary and the associated moisture plume
will progress northeastward from the southern High Plains into the
northern Plains/Upper Midwest by late Wednesday into Thursday,
bringing showers and thunderstorms along the boundary.

Although forcing will become less concentrated on Thursday over
the Southwest, the shortwave energy will continue to lift further
northward into central U.S. and interact with the remaining
moisture, leading to additional showers and thunderstorms over the
Southwest into the central Plains. Repeated convection/training
will bring another day of flooding concerns, particularly over
areas with saturated soils from preceding rainfall. Therefore, a
Slight Risk of excessive rainfall continues over portions of the
Southwest, while a Marginal Risk expands into the central/southern
Plains.

The upper-level trough over the Great Lakes will continue to shift
eastward and the slow-moving frontal boundary continues to push
southward across the Mid-Atlantic into the Southeast, while the
surface troughs continue to maintain a moist and unstable
environment through Wednesday. Additionally, a coastal low
offshore will bring onshore flow and low-level moisture,
supporting periods of showers and thunderstorms from portions of
the Ohio/Tennessee Valley, Mid-Atlantic, and Southeast. Sufficient
warm moisture and slow-moving storms may lead to flash flooding
concerns across portions of the Ohio/Tennessee Valley into the
Mid-Atlantic and Southeast. Furthermore, localized instability may
develop along the surface trough, leading to severe thunderstorm
concerns across portions of the Tennessee Valley. Further south, a
moist and unstable airmass will persist across southern Florida
leading to showers and thunderstorms that may produce heavy
downpours, leading to flooding concerns through Wednesday.

Otherwise, a strong surface high will bring will bring colder than
average temperatures across the northern/central Plains,
Northeast, and Mid-Atlantic, with highs generally in the 60s.
Across the Pacific Northwest and northern Rockies, above normal
temperatures will begin to cool as showers develop by late week.


Oudit


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






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