Two rounds of wintry precipitation possible Saturday night through Monday morning
ST. LOUIS – While a cold and dry airmass has taken over the region for Friday and Saturday, that will be changing as early as Saturday night for some. Two rounds of wintry precipitation are possible from Saturday night through Monday morning.
The first of these rounds is expected to begin overnight Saturday into early Sunday morning. Precipitation will be light to moderate, but road conditions could deteriorate very quickly after precipitation begins.
There are some questions as to precipitation type, but along and north of I-44 in Missouri and I-70 in Illinois, light snow will spread into the region. To the south, more of a sleet and freezing rain mix is possible. Snow and ice amounts should stay light, but with temperatures below freezing, it won’t take much to make travel hazardous through the morning.
While it is still very early, right now it looks like snow amounts for St. Louis will be less than 1″ and a light glaze of ice will be possible, especially to the south of St. Louis.
As temperatures warm on Sunday, the snow and wintry mix should change over to light rain and freezing rain. Highs on Sunday should climb to the mid 30°s.
There is more uncertainty with a potential second round of wintry precipitation for Sunday night into Monday morning. The question will be how far north rain will move into the region and the corresponding temperatures. For now, a wintry mix of sleet and freezing rain will be possible Sunday night into Monday morning. This means the Monday morning commute could be slick. The good news is that temperatures should climb above freezing fairly early on Monday morning, so any precipitation should change to rain rather quickly.
Rain chances will then continues through Monday and Monday night, but temperatures should stay above freezing for this time period.
MoDOT is encouraging motorists to pay close attention to weather conditions and avoid driving during freezing rain if possible. Even treated roads that have salt could become icy as freezing rain hits the surface.