Wintry precipitation appears headed for southwest Illinois. But will it be snow?

The metro-east area almost certainly will see wintry precipitation later this week.

But what type and how much is still very much up in the air.

Ben Herzog, a meteorologist with the National Weather Service of St. Louis, said Monday afternoon widespread rain will soak the area Wednesday, including possibly some rumbles of thunder. Then, Wednesday night, he said cold air will push in from the north and cause the rain to transition into some type of wintry mix.

“There are several different scenarios that could play out, so we’re having a hard time right now pinning down how much and what type of precipitation we’ll see,” Herzog said.

Herzog noted Belleville and the entire St. Louis region basically are on the southern edge of the weather system. He said there’s definitely room for that southern edge “to wiggle around.”

“I would not be surprised if the St. Louis area saw very little in terms of wintry precipitation or it’s just as likely we could get 2-3 inches of snow. There’s just a lot of uncertainty right now,” he said.

Herzog added sleet or freezing rain could accompany the transition from rain to snow. As of now, he said he does not expect amounts that could cause power outages.

“I hate to ever completely rule anything out, but the likely amounts of freezing rain are less than what you’d normally see to cause power outages,” he said.

As far as storm totals, Herzog said, “Total precipitation across the St. Louis area Wednesday morning into late Thursday night, we’re looking at a pretty good amount of liquid — 2 to 2 1/2 inches. The majority will be liquid on Wednesday into Wednesday night and then there will at least be a portion of it that will be frozen after that.”

Herzog expects all precipitation to conclude by Thursday night.

The National Weather Service recommends keeping plugged into the forecast this week as it develops, www.weather.gov.