The first major winter storm of the season is set to bring a messy mix of snow, sleet, ice, and rain to the area this weekend, creating treacherous driving conditions as many are set to head back to work and school next week.
With this system on the way, WPSD Local 6 has activated a Weather Authority Alert for Sunday into Monday. We expect portions of the area to come under Winter Storm Warnings or possibly even Ice Storm Warnings as this system approaches.
Cold air will settle in place Saturday night into Sunday as a storm system moves in from the southwest. We expect precipitation to begin for most of the area after midnight Saturday night, with a mix of sleet and freezing rain creating dangerous driving conditions for many areas by sunrise on Sunday.
There is still some uncertainty as to the exact track of the low pressure system responsible for this storm. The farther north the low tracks, the more warm air will be pulled in from the south, resulting in temperatures over much of Western Kentucky moving above freezing for a few hours Sunday afternoon. However, a track farther to the south will lead to ice accumulation increasing to the south.
The area likely to see the highest impacts from this storm will be in a zone from near Cape Girardeau, Missouri, to the Route 13 corridor in Southern Illinois. With a longer duration of sleet and freezing rain, a dangerous ice storm with ice accumulations up to at least 1/4 inch to 1/2 inch on flat surfaces. Ice amounts on trees and power lines are typically about one-third of the amount on flat surfaces, but combined with some breezy conditions through the day on Sunday, this could still be enough icing for at least some scattered power outages in these areas.
Farther south, areas near the Ohio River and into Western Kentucky, Sunday morning will be the timeframe of greatest concern for at least 1/10 inch to 1/4 inch ice accumulation, before temperatures possible warm above freezing for a few hours Sunday afternoon. If this system tracks farther south, and this warm up does not occur, higher ice amounts could be possible over parts of Western Kentucky.
Exact ice amounts in storms like this are difficult to forecast because there are multiple factors that determine how effectively ice accumulates. Light to moderate freezing rain actually accumulates more efficiently than heavier freezing rain, which tends to hit surfaces and run off. Also, stronger winds can blow the raindrops off of trees and power lines before they can freeze. Any sleet that falls will decrease the amounts of ice accumulation. Remember that sleet takes the form of ice pellets, like sprinkles on a donut, while freezing rain is rain that falls and freezes like glaze on a donut.
As the wintry mix winds down by Sunday evening, there will be a chance of snow that develops on the back side of this storm system Sunday overnight into early Monday morning. It’s possible that an inch or two of snow could fall on top of any ice, further aggravating road conditions.
Whatever this storm system leaves behind will stick around for a few days as bitter cold descends on the area next week. Once temperatures fall below freezing Sunday, they likely will remain below freezing through at least Friday. Some areas of Southern Illinois that have a coating of ice or snow will end up with a few nights of low temperatures in the single digits by the middle of the week. This extended cold snap will pose a danger to anyone without access to adequate heat, as well as unprotected pets and livestock.
Takes steps now to prepare for rapidly changing conditions on Sunday. Download the WPSD Radar app to monitor the latest forecasts and receive alerts for your location.
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