POTENTIAL SNOW STORM POSSIBLE TUESDAY NIGHT

FEBRUARY 15, 2025 -- Whew, there is A LOT to talk about in this blog post. First, the chance for a little light snow as the rain begins to wrap up early Sunday morning. Then, a blast of Arctic air will filter into the region. That will set the stage for what looks like the best chance for widespread, significant snowfall this season.

Heavy rain will begin exiting Southern Illinois Saturday evening, but as the colder air begins to filter into the area overnight, another batch of moisture looks to slide through the area after midnight. Initially starting as more rain, I expect to see a brief switch to sleet, followed by a change over to snow. While the snow won't last long, there could be a few bursts of heavier snow mixed in. I can't rule out up to 1" of snow falling on grass by 6 a.m. Sunday morning.

Sunday will be a MUCH colder day as afternoon temperatures hover in the upper 20s. Strong northwest winds will make it feel even colder with afternoon wind chills in the 10s. The bitterly cold air is here to stay for a prolonged period of time, as temperatures will remain BELOW FREEZING for around 5.5 days.

Despite the cold air, the pattern will remain very active. Let's get to what I know you ALL want to hear about. SNOW! A system is expected to track across the Mid-South region Tuesday afternoon and evening. With the cold air already in place, this system will produce ALL SNOW in Southern Illinois and whatever falls will stick.

The cold nature of the air will result in much higher snow to liquid ratios than normal. Typically, the ratio is around 1" of liquid to 10" of snow. With this system, the ratio will be closer to 1" of liquid to 20" of snowfall. With upwards of 0.5" of liquid equivalent expected with this system, it's EASY to see where our region has the potential to experience an impactful, if not significant, snowfall.

It's still too early to discuss exact numbers and placement of the heaviest snow, but the probability of at least 3" of snowfall is above 50% for all of Southern Illinois. In other words, if you have plans to travel Tuesday evening or Wednesday morning, then you may want to consider changing them.

In the wake of the snow, dangerously cold air will remain in place for several more days. Afternoon highs in the 10s are expected Wednesday and Thursday. Morning lows in the single digits and wind chills BELOW ZERO are also a possibility through the second half of the week.