ROANOKE, Va. – Although we had a mixed bag of precipitation Sunday morning, we are looking toward more significant wintry weather late Tuesday night and Wednesday of this week. Numbers will be fine-tuned, but we more so want to talk timing and potential impacts with you.
Let's get started!
THE BIG PICTURE
High pressure to the north will wedge some colder air into southwest and central Virginia, while low pressure from the south brings in the moisture. When colder air and moisture mesh, it's usually a good recipe for a winter storm.
It would not at all surprise us to see Winter Storm/Winter Weather alerts issued by the National Weather Service at some point Monday (24-36 hours prior to the system's arrival).
MULTIPLE PRECIPITATION TYPES
On December 9, we knew that everything that fell would be in the form of snow. This time, however, that's not the case. That's also not cause for celebration, as this storm could be messier.
While cold air may be wedged at the surface, some warmer air may move in above us. Warm air over warm air leads to rain. Warm air over a shallow layer of subfreezing air leads to freezing rain. A shallow layer of warm air over a thicker layer of subfreezing air leads to sleet. Lastly, subfreezing air over subfreezing air leads to snow.
TIMING THINGS OUT
So while things may start out as snow near I-77 and then spread north through the overnight, a warm layer of air above us will likely change things over to a mix of sleet and then freezing rain by Wednesday morning. Cold air at the surface will likely be stubborn, which could cause that mix to linger west of the Parkway through the afternoon. That ought to make travel quite messy on Wednesday.
Areas near and west of the Parkway see the best chance for ice accumulation, with power outages not out of the realm of possibility. (A light glaze is still possible in Lynchburg and Southside.) Plan ahead, as we'll likely see some school schedule changes Wednesday as well.
With all of this in mind, know that we are still fine-tuning the forecast. That means that we'll start putting out numbers and narrowing down time frames Monday and Tuesday. Keep checking back with us for updates on air, online, on social media and on the StormTeam 10 app.