ST. LOUIS — Temperatures are expected to fall today as a cold front slips from north to south. Rain will be limited to spotty showers at worst during the day. Temperatures will drop into the 50s, and maybe even 40s, north of I-70.
Rain showers will move across the region 5 p.m. and 8 p.m. After 8 p.m. the rain will become quite heavy at times, especially in a band along the cold front. This is expected to be roughly along and just southeast of I-44 in Missouri and into St. Louis with the heavy rain spreading into southern Illinois near and south of I-70 overnight.
Heavy rain is likely overnight, especially along and south of I-44 in Missouri and I-70 in Illinois. The rain will begin to let up after 4 a.m. Several inches of rain are likely by sunrise Friday, resulting in flooding of rural roads, poorly drained urban areas, low water crossings and some creeks and streams. Expect at least some road closures late tonight into tomorrow.
Several additional rounds of rain are likely Friday. They should be more scattered and not quite as intense. The rain will end late Friday evening.
Rainfall totals across the viewing area will range from 2 to 4 inches on average. It is certainly possible that a few spots may exceed 5 inches, especially over southeast Missouri into southern Illinois.