Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
857 PM EDT Sat Jun 6 2026
Day 3
Valid 12Z Mon Jun 08 2026 - 12Z Tue Jun 09 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE MID-MISSISSIPPI, LOWER OHIO, AND WESTERN TENNESSEE VALLEYS...

...2030 UTC Update...

The previous forecast remains on track for the bulk of the Slight
Risk from the Middle Mississippi Valley into the Lower
Ohio/Tennessee Valleys. Increasing totals within the deterministic
guidance (3-4" across the Lower Ohio Valley) and a similar set-up
to the prior days all suggest a continued threat for scattered
flash flooding and the potential for higher-end Slight impacts. The
one caveat is that at least based on the current guidance the
greatest potential for heavy rainfall Monday will be offset from
areas that will see the heaviest rainfall on Sunday, leaving less
concern about repeated rounds helping to prime soils. There is less
confidence in the northward extent of the Slight Risk into
northern Illinois and particularly southern Wisconsin depending on
how far north the front retreats.

Putnam

...Previous Discussion...

On Monday, the excessive rainfall risk translates a bit further
north and east into the Mid-Mississippi, lower Ohio, and western
Tennessee Valleys. A strong front over the Great Lakes will retreat
northeastward as the plume of anomalously deep moisture from the
Gulf surges northeastward to replace the drier air mass in place
over the Northeast. A slow-moving negatively tilted trough will
also promote upper divergence and lift throughout the atmosphere
over the Slight Risk area throughout the period. PWATs around 2
inches will be 3 sigma above normal for this time of year across
the region, so many of the storms that form will consist of highly
efficient warm rain processes, which will promote heavy rainfall.
FFGs across the region will average around 2-2.5 inches, which will
be easily overcome by many of the strongest cells, so long as
their forward speed is kept in check. The Slight Risk area was
nudged west over more of southeastern Missouri with this update,
adjusted for expected heavy rainfall and likely lower FFGs in this
region from the Day 2/Sunday period.

Wegman

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