While the country looks on at the destruction caused in North Carolina by this weekend’s tornadoes, N.C. State researchers predict the end is not in sight for inclement weather. They claim there will be higher than average activity in this year’s hurricane season, a continuing trend from last year.
Lian Xie and Montserrat Fuentes, along with research assistant Morgan Lennon, have forecast the Atlantic basin, which includes the entire Atlantic Ocean, Gulf of Mexico and Caribbean Sea, could witness anywhere between 13 to 16 tropical cyclones this season.
While this number is fewer than the 19 hurricanes observed last season, it is still significantly higher than the average 9.6 hurricanes per year over the previous 50 years, from 1950 to 2000.
According to Xie and Fuentes’ research, of the 13 to 16 tropical cyclones predicted for this season, there is a 70 percent chance of a tropical cyclone striking the Southeast coast, though the probability reduces to 40 percent for a hurricane and about 15 percent for a major—i.e. category 3 or above—hurricane.
In numbers, between seven and nine hurricanes are expected in the Atlantic Basin alone, with three to five being major hurricanes. Both estimates are higher than the corresponding average values of the past 50 years, 6 and 2.3, respectively.
Lian Xie, professor of marine, earth and atmospheric sciences, used data from the previous 50 years to identify important predictors for this season. Using these variables, Xie worked with Fuentes, professor of statistics, and statistics graduate student Lennon to come up with a prediction using statistical models.
“The process of forecasting combines knowledge of meteorology and oceanological science and statistics,” Xie said. “Using our knowledge of science, we find the most effective predictors for storms and then use statistics to prepare models.”
According to Xie, the research team used both past and present statistics to predict hurricanes.
“Statistical models help in quantifying the correlation between the different predictors,” Xie said. “It also allows us to use historical data and identify both spatial and temporal patterns.”
Lennon, who worked with the two professors in preparing the statistical model, says that the estimates were prepared after a careful analysis of the data.
“The given estimated numbers [13-16] have the highest probability of occurring, at about 10 percent each,” Lennon said. “This season is, therefore, going to be a little more active than average— but not as active as last year.”
Lennon also explained the statistical technique used for preparing such climate-based estimates.
“We used a technique called Principal Component Analysis, or PCA,” Lennon said. “Using a handful of climate indices shown to affect hurricanes in the past years, we ran a lot of forecasts and averaged them to arrive at the final estimate.”
A major shortcoming of such forecasts, however, is they tell nothing about the location of these storms, according to the group.
Lennon said we can be fairly sure a larger number of storms will form, but there is no specific information about the exact, or even estimated, locations for these storms.
“We can’t be specific about where we will get them. For example, we can’t predict if there will be any storms somewhere specifically in North Carolina. All we know from these numbers is that they can be anywhere over the entire Atlantic coast,” Lennon said. “This is a limitation of our current technology and forecasting techniques, but we still have a broad sense of what’s coming up for this season.”
Fuentes was out of town and could not be reached for comment.
