HUM 20260801

Posted 3 pm on Friday, 31 July 2026

Based on the 2:26 pm NWS Weather Briefing for 31 July 2026

Marginal Severe Weather Risk Saturday, August 1

Clinton County may experience multiple rounds of showers and thunderstorms Saturday, with the greatest concern during the afternoon and evening. The primary threats are excessive rainfall, dangerous lightning, isolated damaging wind gusts, and a low but non-zero risk of a brief tornado.

Hazards in Order of Risk

1. Excessive Rainfall — Elevated Risk Countywide: All of Clinton County is under an

Elevated Risk for excessive rainfall. Scattered flash flooding is possible, and some flooding could become significant where thunderstorms repeatedly move across the same area.

The most vulnerable locations include:

• Urban and poor-drainage areas

• Roads that commonly collect or cross high water

• Small streams and drainage channels

• Low-lying areas

Rainfall amounts will vary considerably across the county. Some locations may receive manageable rainfall, while others could experience much heavier totals over a short period.

2. Dangerous Lightning — Elevated West, Limited East: The western half of Clinton

County is under an Elevated Risk for lightning, meaning numerous thunderstorms with dangerous cloud-to-ground lightning are expected. This includes:

• Port William

• Wilmington

• Midland

• Westboro

• Western portions of Martinsville

The eastern half of Clinton County is under a Limited Risk for lightning, where isolated to scattered thunderstorms with dangerous cloud-to-ground lightning are expected.

Lightning can occur well outside the heaviest rainfall. Outdoor activities should be prepared to move indoors quickly when thunder is heard.

3. Severe Wind Gusts — Marginal Risk: Clinton County is under a Marginal Risk for

severe thunderstorm winds, representing up to a 15% chance of wind gusts of 58 mph or greater occurring within 25 miles of a location.

Any stronger storm could produce:

• Downed tree limbs

• Isolated downed trees

• Power-line damage

• Localized power outages

• Loose outdoor objects becoming airborne

The damaging-wind threat is expected to be isolated rather than widespread.

4. Isolated Tornado — Marginal Risk: Clinton County is also under a Marginal Risk for

an isolated tornado, representing up to a 5% chance of a tornado occurring within 25 miles of a location.

The tornado threat remains low, but a brief tornado cannot be ruled out with the strongest storms. Residents should have multiple ways to receive warnings and be prepared to move quickly to a basement or small interior room on the lowest floor if a Tornado Warning is issued.

Timing

The primary severe-weather window is expected from approximately 2:00 p.m. through 10:00 p.m. Saturday.

Heavy rainfall and localized flooding could continue through approximately midnight, especially where repeated thunderstorms move across the same area. Additional showers and thunderstorms remain possible into Sunday, although the overall severe-weather and flooding risk is expected to decrease.

Clinton County Information

Saturday’s threat will depend heavily on how much cloud cover and rainfall occur earlier in the day. More cloud cover could limit storm strength, while breaks in the clouds and additional heating could allow stronger storms to develop during the afternoon.

The greatest lightning concern is currently across western Clinton County, while the excessive-rainfall threat covers the entire county. Residents near flood-prone roads, small streams, and known drainage trouble spots should monitor conditions closely and should never drive through a flooded roadway.

Clinton County EMA will continue monitoring updates from the National Weather Service and Storm Prediction Center. Forecast details may change as the timing, storm coverage, and placement of the heaviest rainfall become clearer.

Plan. Prepare. Protect.