Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
452 AM EDT Wed Sep 23 2026
Day 2
Valid 12Z Thu Sep 24 2026 - 12Z Fri Sep 25 2026

..THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM PORTIONS OF
NEW MEXICO INTO SOUTHWEST KANSAS...

...Southwest and Southern Plains...
Heading into Thursday the strongest mid level forcing and highest
PW anomalies will shift northward out of NM and into Colorado and
the Central Plains. However, in the wake of this exiting system,
daytime instability is actually forecast to increase over NM
compared to previous days. While PW values decrease some, they will
remain above the climatological 75th percentile. Additionally,
broad troughing will remain overhead, with embedded shortwave
energy continuing to traverse the region.

With less concentrated forcing and somewhat reduced moisture, the
overall areal coverage of heavy rainfall across NM should diminish
relative to prior days. However, the combination of stronger
instability and sufficient moisture will still support intense
localized convective rainfall rates capable of producing
significant rainfall totals. Given the hydrologic sensitivity built
up from preceding days of heavy rain, an additional flash flood
threat appears likely. While the threat may not be as widespread
as previous days, a Slight risk is maintained, as locally
significant and impactful flash flooding will still be possible.

The Slight risk also extends eastward across the TX and OK
Panhandles and into southwest KS. Convection may be ongoing across
this corridor at the start of the period. Later in the day, in the
wake of the lifting shortwave and surface low, a corridor of
enhanced low level convergence and instability may develop, which
could result in additional rounds of locally heavy convection.
Further west, isolated flash flooding will also be possible across
portions of AZ, southern UT and CO as the trough moves across
these areas.

...Central Plains...
The highest PW anomalies and strongest synoptic forcing will
overlap across KS and NE. This forcing aligns well withe a 1-3"
consensus QPF swath depicted by a majority of the model guidance.
The primary limiting factor for a greater flash flood threat will
be the degree of available instability. Thus rainfall may take the
form of a broad stratiform rain shield with only embedded heavier
convective elements. Therefore, the risk level will be maintained
at Marginal for now, with trends continuing to be closely monitored
for any needed upgrades in subsequent forecast cycles.

Chenard


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