Tornadoes remain wild card in forecasting, experts say

By SETH BORENSTEIN Published: February 23, 2012

— Tornado season is starting, but don't ask meteorologists how bad it will be this spring and summer.

They don't know. They're having a hard enough time getting a fix on the likely path of storms expected in the next 48 hours, from the Ohio Valley to the Southeast coast.

The very nature of tornadoes makes them the wild card of weather disasters. It's just hard to figure when and where they'll appear.

On Wednesday night, one hit Rome, Ga., the National Weather Service said, with winds of 95 mph, leaving a 3-mile swath of destruction.

It's not the first one of the year. In January two people were killed by separate twisters in Alabama. Preliminary reports showed 95 tornadoes struck last month, compared with 16 in January 2011, a particularly stormy year.

The season usually starts in March and then ramps up for the next couple of months, but forecasting a seasonal outlook is even more imprecise than predicting hurricane seasons. Tornadoes are too small and too short-lived. They don't develop like blizzards and hurricanes, which are easier to project.

They pop in and pop out. The storms that give them birth may last only a few hours. Hurricanes and blizzards are lumbering beasts that spend days moving across the satellite maps. When a hurricane approaches, coastlines get days to evacuate. With a tornado, if the weather service can let people know 20 minutes in advance, it's considered a victory.

“The Joplin (Mo.) tornado (that killed 158 people last May) wasn't violent until just about the time it got to the hospital,” said Harold Brooks, a research scientist at the National Oceanic and Atmospheric Administration's National Severe Storms Laboratory, in Norman. “Even when you're in the field, there are still times when you're surprised by the intensity of the event and how quickly it started.”