Winter storm updates, and a peek at a frigid week ahead

Winter has firmly asserted itself across Virginia this Sunday morning. Locally, precipitation over Mecklenburg County has mostly switched over to sleet (it bounces!), with freezing rain (sticks to what it touches) not far behind. How can it not be snowing when surface temperatures are in the teens? Check out this sounding from this morning's weather balloon launch in Greensboro NC:

This is known by weather geeks as a "Skew-T Log P" plot, where height above ground is indicated by the logarithm of the air pressure on the left vertical axis. Temperatures are in degrees Celsius and are skewed from lower left to upper right. The notations on the above chart show that the air temperatures between 900 millibars (~2500 ft overhead) and 700 millibars (~10,000 ft overhead) are above freezing.

Thus snowflakes dropping out of the clouds pass through this warm layer and melt. Then, falling back into below freezing air they refreeze, either as sleet (before hitting the ground) or as rain which freezes when it contacts the ground or any another surface. The latter precipitation type is the concern for the rest of today, as ice will accumulate and create very slippery conditions along with possible power outages.

Precipitation will finally dwindle after sunset this evening. Following afternoon "highs" in the mid-20s tonight's temperatures won't budge much. Monday actually looks like it could warm to slightly above freezing but the winds will pick up as well, gusting over 20 mph at times. The combination of icy tree limbs and power lines coupled with wind could enhance the potential for power outages.

The remainder of the week won't be any warmer. Tuesday could also feature afternoon highs near the freezing mark, but that would be after morning lows in the single digits. The next chance for highs at or above freezing won't be until next weekend.