Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
854 PM EDT Mon Sep 14 2026
Day 2
Valid 12Z Tue Sep 15 2026 - 12Z Wed Sep 16 2026

...THERE ARE SLIGHT RISKS FOR EXCESSIVE RAINFALL OVER PORTIONS OF
THE CENTRAL PLAINS, MISSOURI VALLEY, AND SOUTHWEST U.S...

...Central U.S...

The heavy rain focus over the central states will align with the
slow moving cold front over Kansas, northern Missouri, and western
Illinois where a Slight Risk persists. The Slight was trimmed from
the north, but kept for far southeast Nebraska and southern Iowa
given wet antecedent conditions despite less QPF there. Deep layer
SWly flow will remain parallel to the cold front, promoting
training convection. 12Z guidance favors this repeating rain threat
area to continue farther southwest to the Texas Panhandle where the
Slight Risk was expanded into. PW anomalies of 2 to 3 deviations
above normal can be expected with a swath of actual values around
2". QPF in the 2-4" range are in both the 12Z REFS and HREF with
the HREF favoring northeast KS while the REFS is broader across
northern MO. This area can be considered to have a more enhanced
risk than a general Slight. Scattered flash flooding is considered
likely, especially for overlap from the several inches of rain that
fell north of the KC metro this morning.

The overall risk area continues east along the front across
northern Indiana to Cleveland where the Marginal was expanded.

...Southwest U.S...

The Southwest Monsoon continues in earnest at least through
midweek as an upper high persists over the Mid-South and low
pressure tracks down the West Coast to Northern California.
Moisture anomalies of 2 to 2.5 standard deviations are expected
Tuesday for southern/central Arizona, much of New Mexico, and
over southern Utah through central Colorado. This will be the 4th
day in a row with this pattern leading to increasingly vulnerable
areas/wet antecedent surface. Expanded the Slight areas to include
all of the Slot Canyon Region of southern Utah east to the San
Juans in Colorado as well as more of the Mogollon Rim area in
central Arizona. PW anomalies are less over northern Arizona for
now, but southerly flow is across the region, so further expansion
may be eventually warranted.

Jackson


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