Newswise — On August 28 and 29, University of North Carolina at Charlotte meteorologist Matthew Eastin and his students will be turning North Carolina's coastal Brunswick Co. into one of the country's most densely and carefully monitored weather sites.
The team will be installing five new complete weather stations in the communities of Calabash, Ash, Leeland (which will get two), and Boiling Springs Lakes, supplementing the detailed data already being provided by nine existing coastal weather-monitoring sites in the 855-square-mile county. The new stations are being funded by a faculty research grant from UNC Charlotte.
The aim of the researchers is to get an uniquely detailed, landscape-wide record of severe weather as it occurs " especially in the event that a hurricane passes nearby.
"Our goal is to try to improve the forecast of severe weather " as opposed to the daily forecast of weather that might disrupt a softball game but it's not really going to tear your house down," he said.
In particular, Eastin hopes to find further proof for a new theory that he and other researchers have developed that challenges the conventional view of tornado formation during hurricanes.
With a more detailed analysis, the researchers hope to develop monitoring and forecasting methods that might lead to earlier warning for the tornados that commonly occur in a hurricane's outer rain bands. Hard to forecast accurately, hurricane-spawned tornados develop rapidly across broad areas and generally cause about 10% of a hurricane's total damage.
Eastin points out that hurricane-generated tornados can be a big problem especially because they are so unpredictable.
"You are watching the hurricane move towards the coast and you think, 'Oh, it's making landfall down by Savannah, Georgia, and I live in Myrtle Beach, so I'm clear,' and then, bam!, you get hit by a tornado," he said.
"They happen a lot, and people are caught unaware. Across the Carolinas in 2004 and 2005 alone there were over 130 tornadoes in association with just seven tropical cyclones " none of which actually made landfall on the North Carolina coast " it was just the remnants moving through. It's a fairly important forecast issue for our area."
According to Eastin, part of the problem in forecasting hurricane associated tornados has been that meteorologists have always assumed that the parent storms that spawn the tornadoes do not develop until the hurricane rain bands move onshore.
"The traditional conceptual model is that the individual storms that comprise the hurricane rain bands are 'ordinary' over the ocean, and the increase in surface friction over land creates the miniature supercells," Eastin said. "Supercells frequently produce tornados.
"What we have been finding is that you can actually have these miniature supercells form out over the ocean, and then produce tornados on or very near the beach," he said
The observations that Eastin is interested in collecting will come from his stations, five others maintained by the Renaissance Computing Institute (RENCI) in Chapel Hill and from four RENCI flood sensors. Eastin hopes to collect data detecting sudden wind shifts and abrupt temperature shifts that are tell-tale signs of strong down-drafts and gust fronts, often the pre-cursors to tornado-formation. The information will, in turn, allow him to more accurately identify the specific over-water storms that preceded the dangerous land storms.
"We are trying to provide proof-of-concept through high-density observations," Eastin said. "Ultimately, if we can understand what causes the supercell out over the open ocean, then we can help forecasters to detect them earlier with radar and give everyone a little more forewarning."
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