A winter storm is brewing off Alaska. How will it affect the metro-east?

A part of a storm brewing in the Bering Sea off the west coast of Alaska on Thursday is expected to hit the St. Louis region by Monday night and Tuesday.

But the big question is how much snow will this system produce locally?

If the snow band takes the “northernmost” track, there is a 40% to 70% chance the St. Louis area could get at least 3 inches of snow, according to a map released by the National Weather Service Thursday.

But if it takes the “southernmost” track, St. Louis would have a 70% or greater chance of getting at least 3 inches of snow.

There are places that could get 6 inches of snow depending on the storm’s development, National Weather Service meteorologist Chris Kimble said.

A part of the storm off Alaska is expected to move into western Canada and then dive south into the United States, Kimble said. The combination of colder air from the north and Gulf Coast moisture from the south would produce the snow in the St. Louis metro area.

“Any deviation of how that’s moving on the way to us will change where that heaviest band of snow will fall,” Kimble said. “What we are confident in though is that there will be an area of significant snowfall somewhere in the region. It’s just a matter of whether it will be maybe more southern Missouri and southern Illinois or more towards the north.”

“It’s all a matter of where the heavy snow sets up so it’s certainly possible that St. Louis doesn’t line up for this event and we don’t end up getting a sizable amount,” he said.

The snow is expected to stick on roadways in the areas that receive heavier snowfall.

If metro-east residents don’t see snow, they can expect to get rain with this storm.

In November 2022, some metro-east residents unexpectedly received 6 inches of snow but that storm did not hit the entire St. Louis metro.

The last significant snowfall to strike the entire St. Louis region was in early February 2022, Kimble said.

“It’s been almost two years since we’ve had a really sizable snowfall in St. Louis,” Kimble said.