Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
215 AM EST Thu Jan 8 2026
Day 1
Valid 12Z Thu Jan 08 2026 - 12Z Fri Jan 09 2026

...THERE ARE MARGINAL RISKS FOR EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE MIDWEST & LOWER MISSISSIPPI VALLEY...

Midwest/Lower Mississippi Valley...
A strong shortwave preceding the incoming upper level trough is
expected to bring 500+ J/kg of MU CAPE into portions of the region
during the day on Thursday. The 00z NAM's 2000+ J/kg bulls eye in
KS/MO right at the beginning of the period appears unrealistic/too
high based on recent SPC mesoanalysis MU CAPE trends, though its
trailing instability appears more reasonable, reinforced by the 03z
RAP. The mesoscale guidance advertises small areas of a low risk
of 3"+ across portions of KS, MO, IL, IN, and eventually LA and MS
Thursday night/early Friday morning. While precipitable water
values are in the 1-1.25" range for northern areas and 1.5"+ range
for southern areas, the atmosphere should be well saturated. There
appears to be enough instability to realize local hourly amounts of
1.5"+ where a sufficient number of organized thunderstorms are
able to materialize. Right now, that appears to be the biggest
issue. While it has been dry lately, flash flood guidance values
are modest across much of the area, with 3 hour guidance closer to
3" for the Lower Mississippi Valley, 2.5" for portions of KS/MO,
and 2" for IL/IN. The guidance indicates that the heavy rainfall
should move through quickly, so local amounts of 2-3" within a
couple hours could be enough for isolated to widely scattered
issues, particularly in urban areas. This led to the introduction
of Marginal Risk areas for the areas mentioned above.

Roth


Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt