A winter storm with an icy, damaging history dealt a relatively minor blow to North Carolina last weekend, leaving a slippery glaze but limited power outages in its wake.
After an Arctic front arrived on Friday night to set up a frigid air mass – including afternoon temperatures only in the 20s on Saturday – a low pressure system tracking across the Southeast pulled in a plume of moisture that stretched into the Gulf and even back to the Pacific Ocean.
Warmer air aloft courtesy of that low pressure system caused precipitation to melt before falling into the surface cold layer. It then either refroze as ice pellets (sleet) or reached the ground as liquid raindrops that froze on contact, causing a treacherous icy glaze.
While the effects of this wintry episode are ongoing as roads remain slick and another cooldown is coming with single-digit lows likely on Tuesday morning, this initial lookback has more about the overall accumulations and perspective among other recent ice events.
Accumulations and Impacts
Some forecasts earlier in the week showed the potential for substantial snow accumulations, but once they honed in on the more northward track of the low pressure system – and the mid-level warmth it would bring in – our snow chances mostly evaporated.
Precipitation began as light snow in northern areas including Boone, Wilkesboro, and Eden on Saturday before a changeover to sleet. CoCoRaHS reports showed overnight accumulations of more than 2 inches in Ashe County and an inch or more of snow and sleet across the Triad and Foothills.
For most of the Piedmont, the extreme cold air locked in near the surface ensured that sleet – and not freezing rain – prevailed during most of the event. Sunday morning’s weather balloon data from Greensboro revealed that despite balmy 48°F temperatures less than a mile up, the air closer to the ground was a frigid 7°F.
While the accumulations came as mostly ice pellets, the combined snow and sleet totaled 1.4 inches in Statesville, 0.5 inches in Shelby, and 0.1 inches in Tarboro, making it the first measurable snow of the season at each location.
The greatest freezing rain accumulations of around half an inch occurred between Asheville and Hendersonville. At the statewide peak of about 36,000 power outages on Sunday night, a majority of those were in Henderson and Transylvania counties.
A line of heavier precipitation on Sunday evening also brought freezing rain farther east. Ice accumulations of a quarter-inch to half-inch occurred between Wilson and Ahoskie, including a 0.5-inch thick glaze reported in western Martin County.
That ice, together with wind gusts as high as 28 mph in Rocky Mount, led to a cluster of power outages in northeastern North Carolina, including from a fallen power line in Bertie County.
Outage numbers were slowly declining on Monday morning, and road conditions were also getting better, although they were still ice-covered in many areas. NCDOT noted that main roads such as interstates were beginning to clear up, while many secondary roads were still slick after the weekend snow, sleet, and freezing rain.
Our Latest Ice Event
Any modern ice storm is inevitably compared against the December 2002 event, which was the worst in our state’s recorded history with accumulations of at least three-quarters of an inch from Charlotte through Durham through Roanoke Rapids. That storm left 57% of Duke Energy customers in the Carolinas without power, in some cases for more than a week.
Fortunately, this storm stopped well short of those extreme ice amounts and outage numbers, and was instead on par with more minor ice events from our recent past.
The overall ice accumulations were similar to those on January 22-23, 2016, which saw a half-inch glaze just east of Raleigh and a quarter-inch coating of ice extending into the Sandhills.
Parts of our southern Mountains also saw significant icing this weekend, and this was perhaps the worst ice event there since February 2008. Those areas were included in a rare Ice Storm Warning from the National Weather Service, noting the potential for ice accumulations of more than half an inch, as well as wind gusts of up to 30 mph.
The inches-deep sleet accumulations were reminiscent of the late January 2010 event in parts of the Piedmont and – as an extreme example – the February 1987 storm that saw up to 8 inches of sleet just north of Raleigh.
While this storm turned out to be less severe than expected – and less severe than our neighbors to the southwest experienced – it was still a potent wintry event accompanied by a blustery chill and a street-slickening amount of ice.
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