Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
407 PM EDT Sat Jun 6 2026
Day 2
Valid 12Z Sun Jun 07 2026 - 12Z Mon Jun 08 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR MUCH OF THE
MID-MISSISSIPPI VALLEY, OZARKS, AND THE WESTERN TENNESSEE
VALLEY...


Minimal areal adjustments were made to the inherited Slight Risk
based on the now-available convective allowing (CAM) guidance.
Similar to today, scattered to widespread storms will develop with
daytime heating across the Ozarks vicinity northeastward into the
Mississippi Valley within an extremely humid airmass and under the
influence of an upper-wave lifting slowly northeastward out of the
southern Plains. Additional storms are expected ahead of the
southeastern periphery of the upper-wave along a returning influx
of higher Gulf moisture extending southeast into the western
Tennessee Valley. The airmass characterized with PWATs of 2" will
support highly efficient rainfall processes with rain rates of 2-3"
per hour likely. Within the Slight Risk, two reasons for concern
across the greater Ozarks vicinity are 1) the potential for storm
clustering/cold pool mergers to result in more organized/expansive
storm coverage as well as renewed development along remnant
outflows and 2) that at least some of this region (particularly
areas further south into eastern Oklahoma and western Arkansas)
likely will have seen heavy rainfall today, better priming soils
for potential flash flooding tomorrow. The first concern is
supported by the now-avaialble CAM guidance indicating the
potential for rainfall totals locally as high as 5-7".

Elsewhere, a more isolated flash flood risk remains a concern with
renewed storm development along a quasi-stationary frontal
boundary along/north of the Ohio Valley. Similar to today, moisture
pooling along/south of the boundary will support locally heavy
rainfall rates upwards of 2"/hour, and an eastward extension of the
Slight Risk may be needed with more confidence in storm coverage.
In addition, the main upper-trough to the northwest will begin to
overspread the northern Plains. Robust thunderstorms are expected
to develop and grow upscale southward along a trailing cold front
as surface low pressure intensifies in the lee of the Rockies.
However, the progressive nature of the storms should keep the flash
flood threat isolated.

Putnam

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