April 9, 2009

Could Lightning Predict Intensity Of Hurricanes?

Lightning may provide scientists with crucial insight into predicting the intensity of Earth's deadliest storms.

Each year, hurricanes pose threats of devastation around the world, and while forecasters have become better equipped to predict their pathways, they often find it difficult to gauge the storms' intensity in advance.

Colin Price of Tel Aviv University in Israel and colleagues analyzed the correlation of growth of maximum winds and lightning frequency every 6 hours. Their study consisted of 58 hurricanes worldwide.

Researchers studied the wind speeds of all Category 4 and 5 hurricanes, typhoons and cyclones between 2005 and 2007. That data was compared to global lightning data.

"We find that in all of these hurricanes, lightning frequency and maximum sustained winds are significantly correlated," researchers wrote in the British journal Nature Geoscience.

"The maximum sustained winds and minimum pressures in hurricanes are preceded by increases in lightning activity approximately one day before the peak winds."

"We suggest that increases in lightning activity in hurricanes are related to enhanced convection that increases the rate of moistening of the lower troposphere, which in turn leads to the intensification of hurricanes."

Scientists noted that due to the current capabilities of forecasters to continuously monitor lightning activity, lightning could potentially serve as a way to better predict the intensity of future hurricanes.

"Of the 58 hurricanes analyzed, only two showed no significant correlation between lightning and wind speed," researchers wrote.

Chris Landsea, science and operations officer at the National Hurricane Center in Miami, told USA Today: "One of our biggest challenges is in providing skillful intensity prediction in our one- to five-day forecasts."

"So any method for assisting NHC in these predictions is welcome."

But Joe Golden, a meteorologist with the National Oceanic and Atmospheric Administration, said the new study is "heavy on statistics and weak on the physical linkages between lightning and hurricanes."


On the Net: