Concerning Snow This Evening and Tonight

The weather buzz for the past 72 hours in Bowling Green has revolved around one thing: the chance of snow now through tonight. Though temperatures are in the mid-30s, the lower atmosphere is fluctuating around 32°, resulting in a tug-of-war between sleet and snow. A low pressure system is strengthening and racing up the Appalachians today and out to sea. A lot of moisture is streaming around this low and being wrapped over Kentucky. By primetime, the temp profile of the atmosphere should convert to all snow.

As temperatures drop this evening, the low will be exiting the Carolinas, but the wrap-around moisture will still be in place. Even though we may not fall below freezing until late tonight, it will be cold enough aloft after sunset for a changeover to occur. Look for the rain/snow/sleet mix to continue through daylight, with a full transition to snow coming shortly afterwards.

The 12Z run of the 4km NAM did a good job of modeling the rain and snow coverage at noon over the area

Model runs over the past 24 hours have been speeding up the progression of the low, meaning that by the time the atmosphere becomes conducive for snow, we won't have very long before the precipitation departs our region. As we get closer to the actual event. models have been coming into better agreement regarding timing and accumulation. The NAM, GFS and Euro have not been very excited in terms of how much snow will be on the ground once this is said and done. This evening into the overnight hours, the snow will be mainly light but compact banding may contribute to bursts of moderate snowfall. Having said this, ground temperatures are rather warm, and most of what falls will melt on contact as a result.

As we head into the pre-dawn hours, snow will be the dominant p-type, and surfaces such as grass, sidewalks and elevated materials will begin to accumulate snow. The bands of snow should leave south-central Kentucky by sunrise, and we will likely wake up to a little bit of snow on the ground. Emphasis on little. Greater amounts are possible east of I-65, but generally, we are looking at totals of a dusting to a half-inch, perhaps a tenth or two more in isolated spots. It'll be a wet snow, so some roads, especially in rural areas, may become a bit slushy. With an overnight low around the 30° mark, any slush that melts may re-freeze. Please use a some extra caution if you are out on the roads tonight and tomorrow morning, as some spots may be slick and/or icy.

HRRR 15Z run indicates a few tenths to a half inch of snowfall across south-central Kentucky. Keep in mind that this is the raw total falling from the sky. Actual totals may be less due to melting.

Clouds clear out quickly on the back side of this system for Saturday, leaving us with mostly to partly sunny skies. The added sunshine will assist in reaching an afternoon high in the mid-40s, with winds becoming southwesterly.

- Caleb Chevalier