The National Weather Service in St. Louis has issued a Flash Flood Warning until 10 p.m. Thursday for Monroe and St. Clair counties.

At 3:14 p.m., the NWS said Doppler Radar indicated thunderstorms with very heavy rainfall across the area. A trained weather spotter reported nearly 2.6 inches of rain in Waterloo since midday, along with some street flooding in Waterloo and throughout the county. There were reports of water on the roadway on Route 156 in Foster Pond at about 3:30 p.m.

“This rainfall, combined with the heavy rain from this morning and additional thunderstorms this evening, will produce a flash flood threat across the area,” the NWS stated in its alert. “Runoff from this excessive rainfall will cause flash flooding to occur.”

At 3:55 p.m., police called Bluff Road south of Valmeyer past KK Road impassable and were considering shutting a portion of the road down because of flooding. The 2000 block of Bluff Road was also impassable due to high water.