Winter storm expected this week in southwest Illinois region. Here’s what we know so far

The metro-east can expect more precipitation this week, said Matt Beitscher, a meteorologist for the National Weather Service in St Louis.

Beginning Monday night, strong thunderstorms will move through southeast Missouri and southwest Illinois and continue through the first half of Tuesday.

“We think the main threat for tonight is areas of flooding in Illinois,” Beitscher said. While some of that flooding may reach Belleville, he said that it’s more likely south of Belleville.

On Tuesday, temperatures will start to cool and no precipitation is expected overnight.

Beginning Wednesday, though, a winter storm will start to build.

“That winter storm will come in two waves,” Beitscher said.

The first wave will begin Wednesday afternoon into the evening, bringing mixed precipitation. Beitscher said they’re expecting the precipitation to be mostly sleet, possibly with some freezing rain.

Overnight, there will be a lull in precipitation, before the second round of precipitation starts in time to affect the Thursday morning commute; this round will be a mixture of sleet and snow.

Beitscher said that the interference with Thursday morning’s commute is more about the timing of the second wave, not any especially high accumulations of sleet, freezing rain or snow.

By Friday, the region should dry out, but the weekend temperatures will be lower than normal. This time of year, Beitscher said the highs are usually in the low 40s, but this weekend they’re expecting highs in the low 30s.

Over the last several weeks, St. Louis and the metro-east have been undulating back and forth between warm and cold, which Beitscher said is a pattern that creates the conditions for more precipitation.

“You get the kitchen sink: flooding, winter weather, all sorts of hazards,” he said.

This story was originally published February 21, 2022 at 1:27 PM.