A flash flood watch is in effect until noon Friday for much of the Miami Valley, including Butler, Clark, Greene, Montgomery and Warren counties.
Showers and thunderstorms this afternoon and into the overnight hours may produce heavy rainfall of 1 to 2 inches on saturated grounds, the National Weather Service in Wilmington said.
Poor drainage areas, creeks, streams and ditches will have the highest chance of experiencing flooding.
People in the watch area should keep an eye on the weather and be prepared for immediate action should heavy rains and flooding occur. Avoid low-lying areas, and be careful when approaching highway dips and underpasses, the NWS said.
Temperatures are expected to fall to a low of 63 degrees tonight. Overnight, the forecast calls for more showers and possibly a thunderstorm.
That rain and chance of a thunderstorm will push into Friday morning, with showers gradually lessening through the day. The high will be near 67 degrees. By Friday night, it should be mostly cloudy but with much quieter conditions. However, the temperature will drop way down to around 29 degrees.
For the start of the weekend, the rain is predicted to clear out, though it will stay cold with a high near 40 degrees, despite mostly sunny skies. Saturday night, we will see some more clouds, and temperatures will drop again, down to around 27 degrees.