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...

--- MBSE BBS v1.1.7.2 (Linux-x86_64)
 * Origin: Outpost BBS * Johnson City, TN (618:618/1)