Near record-high temperatures are expected Thursday for the metro-east.
The high will reach 89 under sunny skies, according to the National Weather Service. That's four degrees short of the all-time high of for Sept. 17 in the St. Louis metropolitan area, 93 set in 1997.
Skies will become increasingly cloudy overnight with a 30 percent chance of rain moving into the area near midnight. The low will be 69.
The 30 percent chance of rain will continue into Friday when the high will reach 90, threatening the all-time record high for Sept. 18, 92, which was set in 1998.
Friday night, the chance of thunderstorms is pegged at 70 percent with the likelihood of wet weather increasing as the evening goes on. The low will be 66.
The heat wave will be short-lived with much cooler temperatures expected by the weekend.
There is a 20 percent chance of showers Saturday when the high will be 74. Saturday night, the low will drop to 52 under mostly clear skies.
It will be mostly clear Sunday with a high of 73. Sunday night will be partly cloudy with a low of 52.