Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
409 AM EDT Mon Aug 3 2026
Day 2
Valid 12Z Tue Aug 04 2026 - 12Z Wed Aug 05 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
SOUTHERN ARIZONA...

...Southwest/Southern High Plains...

Shortwave energy rotating around the base of the ridge will briefly suppress
it and cause lowered heights. The combination of this locally
intense ascent into favorable thermodynamics will again result in
scattered to widespread thunderstorms, with some organization
possible through 25-35 kts of bulk shear. Slow storm motions and
heavy rain rates above 1"/hr will produce at least a local flash
flood risk over vulnerable terrain features and burn scars from
southern Colorado through southern Arizona, with the greatest
concentration across south-southeast Arizona with a Slight Risk
area was maintained for this period.

...Southern/Central Appalachians into the Mid-Atlantic States...

Cool air aloft along with ample moisture and instability could lead
to hourly rain amounts up to 2.5 inches, which would be
problematic in rugged terrain, sensitive soils, and urban areas.
Recent rain will keep soils sensitive for potential flooding
issues. The Marginal Risk area was maintained across the eastern
Tennessee Valley/Southern Appalachians to the Mid-Atlantic
coastline.

...Central Plains into the Upper Midwest...

Showers and thunderstorms will fire up along and ahead of a slow
moving cold front sinking southward into the Central Plains and
extending into the Upper Midwest. PW values up to 1.75 inches will
be drawn into the system. Mean winds parallel to this front and a
shortwave tracking along it will help to spawn training
thunderstorms with rainfall rates of 1+"/hr, leading to a narrow
corridor of as much as 3" of rain which may result with instances
of flash flooding.

Campbell/Weiss


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