Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1133 AM EDT Mon Sep 28 2026
Day 2
Valid 12Z Tue Sep 29 2026 - 12Z Wed Sep 30 2026

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FROM THE
SOUTHWEST INTO THE SOUTHERN HIGH PLAINS...

...Southwest to the Upper Mississippi Valley...

Widespread heavy rain and potential numerous instances of flash
flooding are expected to continue across portions of the Southwest
while spreading into the southern High Plains this period. Model
consensus depicts the remnant mid-to-upper level energy associated
with Tropical Cyclone Polo becoming incorporated within the upper
trough moving across the Southwest. As the trough moves east, this
will bring the better forcing and focus for heavier rains farther
southeast into southeastern Arizona and New Mexico, including the
extremely vulnerable southeastern parts of New Mexico. A strong
low level jet is forecast to develop from eastern Mexico to the
central Great Plains as the trough shifts eastward, contributing
an additional influx of deep moisture to parts of the southern and
Central Plains. The heaviest amounts of the period will focus over
the juncture of the Texas Panhandle, northeast New Mexico and
southeast Colorado as this moisture interacts with increasing
ascent afforded by strong mid- to-upper level forcing. A broad
Moderate Risk was maintained from south-central Arizona to the
Panhandle Region and north into  western Kansas.

A Slight Risk was also maintained farther to the northeast across
parts of the Central Plains into southern Minnesota, where
moisture from the south pooling ahead of a surface-to-low level
cold front and ahead of the remnant tropical system will support
the growing potential for heavy rainfall.

Campbell/Pereira


Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt