336
FXUS01 KWBC 281924
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
323 PM EDT Mon Sep 28 2026

Valid 00Z Tue Sep 29 2026 - 00Z Thu Oct 01 2026

...Potentially life-threatening flash flooding expected from the
Southwest into the southern High Plains into early Wednesday...

...Significant flash flooding threat shifts into north-central
Texas Wednesday, with heavy rain and river flooding concerns
spreading into the central Plains and Upper Midwest...

...Dangerous heat continues in South Texas, and much of the East
turns unseasonably warm...

A multi-day and potentially dangerous flash flood event is getting
underway across the Southwest as a strong upper-level low moves
inland from California, crossing Arizona on Tuesday before
reaching New Mexico by Wednesday. Ahead of this system, tropical
moisture from the remnants of Hurricane Polo, which is forecast to
move across Baja California tonight and into northwest Mexico on
Tuesday, will be drawn northeastward into the region. Moisture
levels this high are rare this late in the season. Combined with
robust lift from the upper low, they will support torrential
rainfall rates and repeated rounds of storms over the same areas.
Moderate Risks of excessive rainfall (level 3 of 4) are in effect
from Arizona and southern Utah into New Mexico, far west Texas,
and the southern High Plains, and Flash Flood Watches cover much
of the region. Numerous instances of flash flooding are expected,
and some could become life-threatening, particularly Tuesday into
Tuesday night when the heaviest rain is likely to fall after dark.
Burn scars, urban areas, and normally dry washes will be
especially vulnerable. A few severe thunderstorms with damaging
winds are also possible Tuesday across the southern High Plains.
Temperatures across the Desert Southwest will run well below
average under the clouds and rain.

By Wednesday, the moisture plume will surge northeastward along a
slow-moving front from the southern High Plains to the Upper
Midwest. North-central Texas is a particular concern. repeated
rounds of intense storms Wednesday night could produce significant
flash flooding there, and another Moderate Risk is in effect.
Farther north, a soaking rain from the central Plains into Iowa,
southern Minnesota, and Wisconsin could lead to scattered flash
flooding and rising rivers. Behind the system, a cold front
dropping south from Canada will bring noticeably cooler air into
the northern Plains by Wednesday.

Farther east, the weakening nor`easter will exit into the Canadian
Maritimes by Wednesday. High tides will still bring coastal
flooding at times to part of the Southwest and Mid-Atlantic
coasts. High pressure building in behind the storm will bring dry
weather and a warming trend, with highs near 90 degrees across the
Southeast by midweek, while heat indices in South Texas exceed 105
degrees. Out West, a Pacific front will bring rain to the Pacific
Northwest on Tuesday, and offshore winds will begin a significant
warning trend across California.


Eovino


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






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