ST. LOUIS — In the wake of a strong storm system that brought heavy rain and strong storms to Missouri and Illinois earlier this week, colder air has returned. The large weather system responsible for all the weather changes this week continues drifting east across the Great Lakes Friday afternoon. Friday morning low temperatures were in the upper 20s to lower 30s west of St. Louis.
As any clouds clear Friday evening and the wind diminishes, the coldest air will be focused on areas a bit father east than early Friday. Temperatures will drop to around or just below freezing around the St. Louis metro area east into Illinois. By early Saturday morning, temperatures are expected to drop into the upper 20s to around 30 over the eastern portion of the 5 On Your Side viewing area. Frost is expected to be widespread across eastern Missouri and freezing temperatures are expected across a good portion of Illinois.
A freeze warning is in effect for many of our Illinois counties with a frost advisory for the St. Louis area and many of our Missouri counties for early Saturday morning. Sub-freezing temperatures as low as 28 degrees are expected in the freeze warning.
While the growing season is young, much-above-average temperatures in February resulted in the early growth of some sensitive plants. Newly planted perennials and any annual tender plants may require protection. While Friday morning is likely to be the coldest morning this week from St. Louis and points west, frost may be more likely Saturday morning, especially in Illinois.
Warmer weather will return after Saturday morning. Rain chances will increase late Saturday night into Sunday, especially Sunday morning. While a few rumbles of thunder are possible, strong to severe thunderstorms chances are quite limited.
The Weather First Team will use "Storm Alert" to refer to life-threatening or major-impact weather conditions in our region. "Weather Alert" refers to nuisance or disruptive weather and is indicated by orange icons and bars in our weather graphics on TV and online.
