776
FXUS01 KWBC 220623
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
221 AM EDT Tue Sep 22 2026

Valid 12Z Tue Sep 22 2026 - 12Z Thu Sep 24 2026

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

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

...Severe Thunderstorm Threat across portions of the Southeast
through Tuesday...

A upper-level low/trough will dig into the Southwest and interact
with both the Pacific and Gulf moisture, leading to showers and
thunderstorms across portions of the Four Corners, southern and
central Plains/Rockies, and the Great Basin. The combination of
deep tropical moisture, sufficient instability, and upper-level
forcing will lead to high rainfall rates and excessive rainfall
across portions of the Four Corners and western Texas on Tuesday.
Additionally, WPC has issued a Moderate Risk (level 3/4) of
excessive rainfall for southern New Mexico, while a broader area
of Slight Risk (level 2/4) covers much of New Mexico. The flash
flooding threat is expected to increase on Wednesday, as the
primary shortwave energy lifts northward through New Mexico.
Therefore, the Marginal and Slight Risk for excessive rainfall
will expand into central Plains, while a broad area of Moderate
Risk will encompass much of eastern New Mexico. The southwest
moisture will gradually transport northeastward along a
slow-moving boundary, bringing showers and thunderstorms across
the northern/central Plains into the Upper Midwest by late
Wednesday into early Thursday.

Furthermore, a upper-level troughing over the Great Lakes will
gradually shift eastward toward the Mid-Atlantic and Northeast,
while the frontal boundary will settle southward across the
southern Plains into the Southeast, Ohio Valley, and Mid-Atlantic.
A developing coastal low offshore will help maintain low-level
moisture ahead of the slow-moving frontal boundary, supporting
period of showers and thunderstorms from portions of the Ohio
Valley/Mid-Atlantic into the Appalachians and Southeast. Pockets
of elevated instability may develop along the frontal boundary,
leading to severe thunderstorm concerns across the Southeast.
Additionally, slow storm motions and efficient warm moisture will
lead to locally high rainfall rates within the strongest storms,
leading to flash flooding concerns over portions of the Ohio
Valley/Mid-Atlantic and Southeast.

By Wednesday, the boundary over the Mid-Atlantic and Ohio Valley
will move further south, but shortwave troughs will reinforce
another round of showers and thunderstorms across the area. This
will lead to another day of flash flooding concerns over the
Mid-Atlantic and Ohio Valley, especially over areas where soil
remains saturated from previous rainfall. Further south, a moist
and unstable airmass will persist across southern Florida leading
to scattered to numerous showers and thunderstorms, with locally
heavy downpours possible through Thursday.

Temperature-wise, a strong surface high will bring colder than
average temperatures across the northern/central Plains into the
Mid-Atlantic and Northeast behind the frontal boundary, while the
southern Plains into the Southeast will remain warm and humid.

Oudit


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






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