All Winter Modes in Play with Tonight's Storm

Just when we thought this was going to be yet another boring winter, Mother Nature relentlessly tosses curveballs as us. First came the biggest snow in the region since 1968, followed by another one to two inches just when the roads were becoming clear. This was proceeded by record-shattering low temperatures and dangerous wind chills for two days. And now we find ourselves awaiting an absolute mess of a winter storm, right on the heels of it all. A Winter Storm Warning is in effect for our entire coverage area until 6 AM Saturday morning.

I'd briefly like to point out that the lowest temperature ever recorded in the state of Kentucky was -37°, back in 1994. Climate data from the National Weather Service does not consider readings from Mesonet stations, but here's how they looked statewide this morning.

Lows recorded across the state last night by the Kentucky Mesonet

Now, onward to the forecast. We're spying another low pressure center rise up from the southwest and skirt the Ohio Valley. As it approaches, it's being wedged between a high to our north. Like a sponge, the atmosphere will squeeze out precipitation. There is a lot of moisture intact too; some models indicate that over 2 inches of water will fall in some form. And there is the tricky part. We have a layer of warm air aloft trying to work its way over the area. How far north it progresses remains to be seen, but guidance suggests that this warm tongue of air will advance to about the Ohio River. Places along I-64 should see primarily snow, but several thousand feet up above south-central Kentucky, the air will be above freezing by tonight, meaning precip would be conducive to fall as rain.

Meanwhile, we're still quite cold at the surface, partially because there is still so much snow on the ground. Ergo, surface temperatures are below freezing and will stay that way until the early morning hours tonight. As the warm air aloft pushes in, expect precip to start as a sleet/snow mix before transitioning to rain this evening. We know what happens when rain falls on a freezing surface though: freezing rain. Therefore, it looks like some accumulations of ice are possible tonight as well. Not what we needed.

A look at the expected conditions at 11 PM tonight Bowling Green time by NWS Louisville

Let's talk impacts. Snow totals should be very minor, but sleet may accumulate briefly before the freezing rain sets in. Ice totals could run in the amounts of a tenth to three-tenths of an inch before we warm up beyond freezing at the surface late tonight. Such accumulations can bring down branches and perhaps power lines, not to mention making roadways extremely slick. If there's any good news, we're expecting a lot of plain old rain through most of Saturday. Rain in the gauge may surpass 2 inches by tomorrow night. A great deal of rain may help to erode any layer of ice, but it would also start to melt out the drifts of snow. So this in turn brings up a flooding issue. NWS Louisville has stated that the greatest threats for urban flooding would be in our neck of the woods.

Either way you slice it, please be careful on the roads tonight and do be prepared in the event of a loss of power. We got through this last week and we can weather the storm this time. It is also worth mentioning that confidence is not high with this forecast. A shift of the low by 20-30 miles or the difference between 32-33° makes a very different outcome. We'll be straddling the border of that freezing mark for several hours, and a slight waver in either direction can dictate between more ice/sleet or none at all. Should any additional warnings or alerts be issued, we'll pass them along.

- Caleb Chevalier