Weather is most interesting when it doesn’t do what we expect.
We expect thunderstorms on a July afternoon. We don’t expect howling winds and thunder after midnight in mid-November, but that’s exactly what we experienced on Tuesday evening.
Throughout the morning and afternoon, forecasters and computer models indicated the likelihood of severe weather during the evening hours. Around 8 p.m., the Storm Prediction Center issued a Tornado Watch extending roughly from Charlotte to Raleigh. Though no tornadoes were observed, some of the storms around Charlotte exhibited threatening rotation. Considering North Carolina’s history of November tornadoes, this was undoubtedly a wise move.
As the line of storms pushed to the east, the storms took on an arc-like appearance and wind damage began to strike. Throughout the 11:00 p.m. hour, the local National Weather Service office issued warnings for Durham and Wake Counties. The line of storms passed through Raleigh just after midnight. Local observers measured wind gusts as high as 35 mph.
Progress Energy reported numerous small power outages across the region where trees had fallen on power lines. Overall, the Storm Prediction Center received 82 reports of damaging wind throughout the Carolinas and Mid-Atlantic.
So what happened to cause this unexpected weather?
Typically, thunderstorms won’t form without moisture, warm temperatures, and something to lift the air upwards. With the additional element of spin, you can add tornadoes to the mix.
On Tuesday, we had ample moisture and spin in the air. Temperatures climbed into the upper 60s leading up to the storms, which provided a limited but important source of energy. For the past three days, highs had run about six degrees above average.
A cold front pushing east from the Appalachian Mountains provided the lift to get the storms going. Aloft, winds were rushing along at 40 to 60 miles per hour. The storms actually forced these winds to the surface, which caused the widespread damage.
Severe weather is less common in Nov. than during the spring and summer months, but it isn’t totally unprecedented. According to information from the National Climatic Data Center, 80 tornadoes have touched down in North Carolina during the month of November since 1950. When tornadoes do happen, they can be particularly damaging. Nov. tornadoes account for only seven percent of all tornadoes, but 14 percent of tornado injuries.
On Nov. 15, 2008, eight tornadoes touched down throughout the I-95 corridor between 1:00 and 4:00 a.m. A strong tornado tracked through Johnson and Wilson counties, killing two and injuring six.
A similar tornado devastated the small town of Riegelwood in Columbus County at 6:37 a.m. on Nov. 16, 2006. The storm left behind a half-million dollars in damage and eight deaths.
Two separate tornado outbreaks on Nov. 4 and Nov. 23, 1992 spun up 27 tornadoes across all corners of the state, injuring 67. Two died when a tornado struck Orange County in the early-morning hours of the 23rd.
This list would be incomplete without mentioning the Raleigh tornado of Nov 28, 1988. A major F-4 tornado began just east of RDU airport shortly after 1:00 a.m. The tornado tracked to the northeast through the Glenwood, Creedmoor, and Six Forks areas. It remained on the ground through Wake Forest, and spun eastward into Franklin, Nash, Halifax, and Northampton Counties. Four died and 157 were injured, which is a remarkably low total for a tornado to strike a major populated area when most people were asleep. Hundreds of homes and businesses were devastated, and the disaster ultimately cost $142 million (adjusted to 2010 dollars).
If you’re interested in finding out more about these cases, the National Weather Service Office in Raleigh collaborates with N.C. State researchers to publish detailed summaries of winter storms, tornado outbreaks, and hurricanes throughout the state’s history. You can find them at weather.gov/rah/events WRAL also features a full-length documentary of the 1988 tornado and its aftermath online.
