Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
756 PM EDT Sat Jul 25 2026
Day 3
Valid 12Z Mon Jul 27 2026 - 12Z Tue Jul 28 2026

...THERE ARE MARGINAL RISKS OF EXCESSIVE RAINFALL MONDAY ACROSS
THE FOUR CORNERS STATES TO CENTRAL PLAINS AND GREAT LAKES/OHIO
VALLEY...


...Four Corners States into the Central Plains...
Elevated amounts of moisture will linger over the Four Corners
region given a persistent monsoon pattern, although guidance still
points to a gradual southward shift in the placement of the upper
high center. This may slightly reduce thunderstorm coverage in
areas like Utah to the Four Corners themselves, but a weak
shortwave looks to move across Colorado and vicinity Monday into
Monday night and enhance convection there and spreading into the
central Plains overnight. Maintained a Marginal Risk area in the
Four Corners states and extending eastward into the central High
Plains to cover the isolated flash flooding threat. Plots of ECMWF
PW anomaly plots continue to prove helpful in highlighting areas of
increased concern.


...Great Lakes and Ohio Valley into the Northeast US...
By Monday a more potent shortwave will move southeastward through
the Upper Great Lakes region rounding the Rockies/High Plains high.
Difluent flow ahead of the shortwave will eventually lead to the
consolidation/strengthening of a low pressure system during the
period. This low is expected to help forcing for heavier rainfall
over the Great Lakes/Ohio Valley, with less model spread than the
Sunday convection likely due to greater forcing. A Marginal Risk
remains in place, but convective activity should be relatively
progressive, which is still expected to mitigate any higher risks
of excessive rainfall.

Tate/Bann

Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt