Milwaukee, Wis. — Southern Wisconsin residents are being urged to prepare for a potentially dangerous stretch of overnight weather, as forecasters warn that thunderstorms moving through the region could bring destructive winds, large hail and heavy rainfall while most people are asleep.
Officials say the evening should remain calm before storms begin developing and pushing south across the state. Two possible timelines are being watched closely — one where a line of storms rolls in between 11 p.m. and 3 a.m., followed by lingering showers into early Monday, and another where the system arrives later, after 3 a.m. Either way, forecasters caution that the threat for severe weather will not disappear.
A large stretch of southern Wisconsin, including communities near Madison, Beaver Dam and Wisconsin Dells, has been placed under an Enhanced Risk for severe thunderstorms — a Level 3 out of 5. Areas farther southeast, including Milwaukee, Racine, Kenosha and Janesville, fall under a Slight Risk, rated Level 2 of 5.
The biggest concern for meteorologists is straight-line wind gusts that could exceed 70 mph, strong enough to snap tree limbs, damage roofs and knock out power in some areas. Large hail and an isolated tornado also remain possibilities as the system moves through. By Monday morning, attention may shift toward slow-moving rain bands capable of causing localized flooding on roadways and in low-lying areas.
Emergency officials are urging residents not to rely on a single source for alerts overnight. Having a charged phone, access to wireless emergency alerts, a weather radio or a reliable weather app nearby before going to bed could make a critical difference if a warning is issued in the middle of the night.
Residents are also being advised to secure loose outdoor furniture and decorations ahead of time, and to know where the safest interior space in their home is — ideally a windowless room on the lowest floor — in case a Severe Thunderstorm or Tornado Warning is issued while they’re asleep.