Overview
- Forecasters say showers and thunderstorms will increase Thursday and become most widespread Friday–Saturday, with the greatest rain coverage in south-central and southeast Montana, Colorado, the Chicago area, Minnesota, and South Florida.
- Local offices and the National Weather Service warn that slow-moving or training storms could produce torrential downpours and localized flash and urban flooding in low-lying and poor-drainage areas.
- Mountainous areas in Colorado face high September moisture that raises the chance of locally heavy rain, minor flooding, and isolated rockslides on steep slopes and burn scars.
- Tropical moisture will reach southeast Texas including Houston, but a strong atmospheric inversion is expected to cap storm growth so forecasters give roughly a 40% chance of storms there Thursday.
- Most forecasts project a brief return to drier, more seasonal conditions late in the weekend or early next week after the main wet episodes pass, though timing and exact rainfall totals remain uncertain so people should monitor local NWS alerts.