Mesoscale Precipitation Discussion 1032
NWS Weather Prediction Center College Park MD
535 AM EDT Thu Aug 13 2026

Areas affected...Eastern NE...Western and Central IA

Concerning...Heavy rainfall...Flash flooding possible

Valid 130935Z - 131535Z

SUMMARY...Heavy showers and thunderstorms continue to advance off
to the east early this morning across the Midwest in association
with a strong MCS. Locally a few inches of rainfall will be
expected, and this will support a threat for some areas of flash
flooding, especially across the more urbanized locations.

DISCUSSION...The latest GOES-E IR satellite imagery shows a strong
cold-topped MCS continuing to advance east across the Midwest,
with the heaviest rains currently impacting eastern NE and far
western IA. The convective complex is associated with ejecting
shortwave energy across the north-central Plains that is
traversing the north side of an elevated instability gradient and
poleward of a stationary front.

MUCAPE values of 1000 to 2000 J/kg are noted with PWs across the
region of locally near 2 inches. This coupled with favorable shear
of 40 to 50 kts and the nose of a strong low-level jet of 40+ kts
riding up toward the IA/NE border should continue to help maintain
this larger scale MCS going well into the morning hours as it
advances east down across western and central IA.

Rainfall rates will continue to be high and capable of reaching
1.5 to 2.5 inches/hour with the stronger storms. In fact, Norfolk,
NE picked up 2.54 inches in one hour from 08Z to 09Z as the core
of the MCS moved through.

The latest 06Z HREF guidance and recent HRRR solutions support
downstream rainfall amounts this morning as high as 3 to 4+
inches. Some areas of flash flooding will be possible as a result.
The more sensitive urban areas will be at greatest risk for seeing
potential impacts.

Orrison

ATTN...WFO...DMX...DVN...FSD...GID...OAX...

ATTN...RFC...KRF...MSR...NWC...

LAT...LON   43209552 43099401 42699235 41959133 41269123
            40799196 40649306 40659491 40809638 41169732
            41819771 42579744 43109665