ST. LOUIS — A Winter Storm Warning has been issued for most of the St. Louis area from noon Wednesday until midnight Thursday. All indications point to us having two distinct waves of winter weather coming.
The first wave is projected to arrive Wednesday afternoon between 1 p.m. and 4 p.m. and last into Wednesday night.
The second wave will arrive Thursday morning, with a ramp-up time between 8 a.m. and noon. It will last into Thursday evening. The precipitation will lighten considerably between the two waves, but it may never completely end.
This is a poorly organized weather system, so the details are even less certain than normal. That being said, impactful winter weather is likely across the entire viewing area. It’s just a matter of hashing out the details.
Referencing the weather map below, the counties in the blue zone (north of Interstate 70) are under a Winter Weather Advisory. This will predominantly be a snow event, but some sleet may mix in from time to time, especially during the second wave. Some freezing drizzle is also likely. Total accumulations of 2 to 4 inches are expected in the blue zone by Thursday evening.
Areas in the pink zone will see a wintry mix on Wednesday that starts as snow and then transitions to a mixture of snow and sleet. Accumulations of 1 to 1.5 inches are possible in the first wave.
The second wave Thursday will be more of a “sleet and freezing rain” setup, with some snow still possible near and just south of Interstate 70. An additional 1/2 inch of snow/sleet is possible along with up to 1/4 inch of glaze ice. This combination of winter weather is the reason this zone is under the Winter Storm Warning.
The red zone is also under a Winter Storm Warning. The area will see a mix of sleet and freezing rain for the first wave and more freezing rain for the second wave.
Significant ice accumulations of 1/4 inch with some sleet accumulation will be possible. Is this a major winter storm? No, not really.
But, it will create significant inconveniences starting Wednesday afternoon and lasting through Thursday. There may even be some lingering issues for Friday morning as road crews work to clear the mess mix.