A stalled frontal boundary is bringing days of flash flood risk to the Midwest and central Plains this weekend.1
Areas already soaked earlier in the week, including Chicago and parts of Indiana and Ohio, face an elevated threat of flash flooding.1
Where the heaviest rain is falling
The heaviest rain through Saturday is expected to stretch from eastern Iowa to southwestern Michigan.1
Local flash flooding is possible in cities including Des Moines, Milwaukee, Chicago and Indianapolis.1
On Saturday, the heaviest rain was forecast to shift a bit farther south and spread east, with two rounds of heavy rain expected.1
How to track the flood threat day by day
Checking a live rain and flash-flood-warning map is the fastest way to see whether your area is under a warning right now.1
Flash flood warnings are shown as green polygons on tracking maps, marking the specific zones where flooding is happening or imminent.1
Because the boundary is stalled rather than moving through quickly, the flood threat is expected to persist over multiple days rather than clearing in a single pass.1
Staying safe if you are in the flood zone
Residents in Chicago, Des Moines, Milwaukee and Indianapolis should follow local flash flood warnings closely while the boundary remains stalled.1
Elsewhere, a rare tornado was spotted in the mountains north of Salt Lake City, Utah, as storms moved through the state.3
That tornado was captured on video by residents and was described as occurring at high elevation, an unusual setting for tornado formation.3
What separates this event from typical thunderstorms
Unlike a fast-moving storm system, a stalled frontal boundary keeps feeding rain into the same corridor for an extended stretch, which is why forecasters are flagging a multi-day threat rather than a single afternoon of storms.1
That repeated rainfall over already-saturated ground is what raises the flash flood risk in cities like Chicago that had already seen heavy rain earlier in the week.1
Practical steps for households in the threat zone
Keep an eye on the live flash flood warning map for your specific location rather than relying on a general regional forecast alone.1
Sign up for weather alerts by email so warnings reach you as conditions change through the weekend.1
Avoid driving through flooded roads, since flash flooding by definition can develop quickly in urban areas such as Des Moines, Milwaukee, Chicago and Indianapolis.1
Common mistakes to avoid during a multi-day flood threat
Do not assume a break in the rain means the threat has passed. A stalled boundary can bring a second or third round of heavy rain on top of already-wet ground.1
The heaviest rain band was expected to shift position, moving south and spreading east on Saturday.1
Do not ignore flash flood warnings just because your neighborhood looks dry at the moment; warnings are issued for specific polygons that can change quickly.1
Budget-friendly ways to stay informed
A free sign-up for weather email alerts is one no-cost way to get updates on flash flood warnings for your area as the boundary continues to affect the region.1
Checking the live rain and warning map does not require a paid subscription and updates in real time as conditions change.1
Safety warning
Flash flooding can develop with little warning in cities across the affected corridor, from eastern Iowa to southwestern Michigan.1
Residents in and near Chicago, Des Moines, Milwaukee and Indianapolis should treat any active flash flood warning as a signal to avoid low-lying roads and areas prone to fast water rise.1
Check the forecast for your city to see how this multi-day rain pattern is shaping up where you live.