ST. LOUIS – It has been a warm and steamy night. At around 2:00 a.m. Tuesday, it was still 87 degrees.
It has been storming most of the night just to the north and northeast of the St. Louis region, but only a few non-severe storms have dropped into Macoupin, Montgomery, and Fayette Counties in Illinois.
Now, an outflow boundary is dropping farther south and that is proving to be the focus line for some showers and storms south of I-70 on both sides of the Mississippi.
Bottom line: Let’s plan for and expect thunderstorms across the region on Tuesday.
Rainfall will be heavy at times and a few severe thunderstorms are possible, especially along and south of I-70 and this evening.
Rain and storm chances will continue into Wednesday morning.
Areas south of I-44 in MO and I-64 in IL remain under a heat advisory. This area will see another day of heat index values above 100 degrees. But the rain and storms will eventually cool everyone down.
Clearing skies Wednesday afternoon and sunshine through Saturday. Highs will only be in the low to mid-80s.
