Foothills Weather Briefing: Next 24 Hours Will Feature Rejoicing of Some Snow Lovers, While Depressing Others

Some of you snow lovers may want to start practicing deep breathing now, because this is shaping up to be one of those classic western North Carolina heartbreak storms. You know the type — you go to bed imagining fat snowflakes drifting past the streetlights, only to wake up and find nothing but your neighbor’s wet driveway mocking you. Meanwhile, five miles up the road, someone’s posting pictures of a “winter wonderland” that looks suspiciously like powdered sugar on a blueberry muffin. That’s the kind of gradient we’re dealing with.

A fast-moving system dropping down from Canada will sweep across the region late tonight into Monday. This will bring a quick round of rain and, in a few spots, a short window where snow may mix in or briefly take over.

As the disturbance passes by, a new low-pressure center will form just off the South Carolina coast. That developing coastal low will pull colder air southward into western North Carolina on Monday morning. At the same time, a narrow band of heavier precipitation may form somewhere across the state. Wherever that band sets up will determine who sees nothing but rain and who sees a quick burst of snow.

Most of our lower-elevation towns and communities should expect mainly rain, with the possibility of some wet snowflakes mixing in late Monday morning. Temperatures at the surface will stay above freezing, so widespread travel issues are not expected.

Higher elevations and the eastern-facing slopes of the mountains have the best chance of accumulating snow for a short period. A quick coating or slightly more could develop on grassy or elevated surfaces if the heavier band passes overhead.

How the Rain Could Change to Snow: Wet-Bulbing

One important part of tomorrow’s forecast is a process called wet-bulbing. This is when dry air mixes into falling precipitation, causing some raindrops to evaporate. When evaporation happens, the air temperature cools — similar to how your skin feels cooler when water evaporates off it.

As the air cools through this evaporational process, temperatures can drop just enough for rain to flip over to a mix or even a brief period of all snow, even if the thermometer was showing slightly above freezing beforehand. Wet-bulbing is often the reason we see a sudden transition to snow during fast-moving or early-season systems like this one.

This effect will be especially important Monday morning. If the air cools quickly enough through wet-bulbing as colder air arrives from the coastal low, some areas — particularly along and north of I-40 and the higher terrain — could see rain change to wet snow for a short time.

Timing

This entire setup evolves quickly. The window for any wintry mix or snow is only about six to eight hours before the system pulls away. Most precipitation will taper off between 1 and 3 pm Monday, ending any chance for snow.

Bottom Line

Expect rain for most locations, with a chance for a brief rain-to-snow changeover late Monday morning. Higher elevations have the best chance for light snow that may briefly accumulate. No major travel impacts are expected, but weather conditions may change quickly — especially in the mountains.