Finger on the Weather

The National Weather Service will be tweaking its hurricane forecasts for the coming season.

Research has shown that it’s not the strength of a hurricane that dictates the size of the storm surge — it’s the hurricane’s sheer physical size, said Kenneth Graham, meteorologist in charge of the New Orleans branch of the National Weather Service.

Recent large Category 2 hurricanes have generated stronger storm surges over larger areas that small hurricanes with stronger maximum sustained winds, he said.

The challenge for forecasters will be to get residents to take seriously storm surge warnings from hurricanes lower on the Saffir-Simpson Scale, which rates hurricane strength by wind speed. The prevailing mindset is that a Category 2 hurricane is less of a threat than a Category 4 or 5, and in some respects — such as storm surge — that isn’t necessarily true.

Greg Carbin, warning coordination meteorologist for the Storm Prediction Center, acknowledged that the false alarm rate for radar-indicated tornadoes is still high. In other words, all too often radar-indicated rotation – which is enough to prompt a tornado warning – doesn’t translate into an actual tornado touchdown. But officials are erring on the side of caution to minimize the possibility of residents being blindsided by a tornado.

Harold Brooks, research meteorologist for the National Severe Storms Laboratory, said tornadoes are possible in many places folks wouldn’t think of — and he had photographs to prove it. One tornado that looked like a classic Great Plains twister was actually photographed in Finland. Another touched down in Venice, Italy. And he had yet another shot of a tornado in South Africa.

But Tornado Alley’s reputation is well-deserved, he said: no place in the world has stronger, longer-lasting tornadoes.