ST. LOUIS — Dense smoke that has been dropping south from Canada has made it into the St. Louis area. Visibility dropped to between 2-3 miles from the Canadian wildfire smoke. A warm front moving in today will help kick the thickest smoke to the east by afternoon.
The worst of the smoke will be around in the morning, with some improvement in the afternoon. However, then ozone will become a concern from midday into the afternoon. Between the two, we expect orange air quality for Wednesday and that means an Air Quality Alert is in effect. That means the air quality will be unhealthy for some with health and breathing issues and within vulnerable populations.
Scattered showers and thunderstorms are still possible this morning as the dome of heat starts to build our way. Rainfall amounts look light, but a few storms could bring brief heavy downpours that could make some folks happy.
High temperatures Wednesday will range from the 80s in Illinois into the upper 90s west of St. Louis. Along and ahead of that same warm front overnight, we’ll watch for some thunderstorms. Overnight temps only drop into the 70s.
Thursday and Friday bring the heat, afternoon high temperatures will be well into the 90s, approaching 100 in many spots. Heat index values will be around 105. There is a chance for a few storms to drop into the area again Thursday evening. That may cap the heat a bit. We’ll have to wait and see.
A cold front Friday night and Saturday helps break the heat for the weekend. It also brings a good chance of showers and storms. A more comfortable Summer day Sunday and Monday. A chance of storms again for Independence Day.