ST. LOUIS (AP) — Punishing thunderstorms weakened Wednesday as they pushed across the Midwest, causing some flash-flooding and minor wind damage in parts of southern Illinois and eastern Missouri.

Widespread heavy rain slowed the commute for thousands of people in metro St. Louis and winds bowled over trees in the central part of Missouri, snapping electricity lines and leaving thousands without power.

That was a far less severe battering than earlier in the storms' track, when baseball-sized hail blasted homes and cars, and flooding forced rescuers in boats to pull residents from homes in Nebraska and Iowa.

The storms also affected primary elections Tuesday in Iowa and South Dakota where voters had to cast ballots by flashlight in areas that lost power.

By Wednesday morning, the crescent-shaped arc of thunderstorms weakened, though winds of up to 75 mph were reported in Columbia, Missouri, with heavy rain and dime-sized hail.

In southern Illinois, the system had diminished enough that no severe thunderstorm or tornado watches were issued.

Forecasters there were already looking behind the storms to a cold front pushing south that could help trigger a new line of severe weather by Wednesday afternoon.

"We could have strong winds, we could have some large hail and there could be an isolated tornado," said Greg Meffert, lead forecaster for the National Weather Service's office in Paducah, Kentucky. "If they manage to pop up they could be severe fairly quickly."