Fickle Fay provides potent hurricane lessons

FORECASTS: As new season nears, 2008's meandering storm still fascinates

National Guard troops search a Melbourne neighborhood flooded by Fay in August. The storm never attained hurricane status, yet dumped over two feet of rain in many areas of Florida.

Published: Wednesday, May 13, 2009 at 1:00 a.m.
Last Modified: Tuesday, May 12, 2009 at 9:52 p.m.

FORT LAUDERDALE - Fay may not be remembered with Charley, Ivan, Wilma and the other devastating storms that have slammed Florida over the past few years.

But emergency responders say they get headaches thinking about Tropical Storm Fay, and the chaotic path it followed across Florida last August still confounds scientists.

Fay, which caused $195 million in damage and killed five people in the state, underscored the danger that even seemingly lesser storms pose. It also highlighted the uncertainty that remains in storm forecasting, despite increasingly sophisticated computer models and remarkable advances in accuracy over the past 15 years.

"The one big lesson was not to underestimate tropical storms," said Steve Letro, meteorologist in charge at the National Weather Service office in Jacksonville, where Fay caused a three-foot storm tide and dumped heavy rains for three days, causing widespread flooding and destroying beachfront homes.

Fay threatened every inch of the state's coast, making landfall here four times, dumping more than two feet of rain in some areas and spawning 81 tornadoes from Palm Beach County to the Carolinas.

Fay nearly gained hurricane strength several times and illustrated how quickly a storm's predicted path and intensity can shift, with tiny changes making major differences in the effects on land -- and people.

"There's a lot we can learn from the storm," said Jack Beven, hurricane specialist with the National Hurricane Center in Miami. "In some cases we need to do some more looking to find out what happened and better anticipate if it happens again."

Fay started as a typical August storm, forming off the African coast and moving to the Caribbean. But on Aug. 15, as it passed near Puerto Rico, it became a tropical storm so fast that forecasters did not realize it until Fay's center was already over the Dominican Republic.

"We recognized when the storm was under way that this was going to be a little bit tougher than average to forecast," Beven said.

The storm was expected to curve through the Caribbean, cross the Keys and shoot north up the Florida Gulf Coast, following a path similar to 2004's Hurricane Charley. The whole Southwest Florida coast was placed under a hurricane watch.

But the storm stayed weak. It slowly crossed Everglades City, farther south than expected, and crawled northeast. Surprisingly, it picked up speed over land, which rarely happens and remains a meteorological mystery.

Forecasters sounded alarms that Fay could move into the Atlantic near St. Augustine and gain hurricane strength over the warm Gulf Stream current before angling back toward land. Meanwhile the storm sent tornadoes twirling into Palm Beach County.

Then it stalled over Melbourne for about three days, dumping 27 inches of rain. Forecasters and emergency workers sat on edge, hoping the storm would move east -- but not too much.

The line between Fay's remaining a tropical storm and tapping warm waters to become a hurricane was just 50 miles.

"We're glad that it didn't, but it just made us look back afterward and say, 'Man that was close,'" Letro said.

The storm did not quit with Jacksonville. It moved across northern Florida. Again forecasters worried about it steering southwest into the Gulf of Mexico, where it could gain hurricane strength and run a treacherous course parallel to the Panhandle.

It stayed on land, however, bending east again, where it carried rain and tornadoes northward.

In retrospect, hurricane scientists say, the storm churned a fine line between inflicting serious damage it caused and escalating into a catastrophic hurricane with high winds and storm surge.

"Little changes in track made big differences in where it wound up," Beven said.

Accurately forecasting landfall from a storm that runs parallel to land is difficult because storms wobble, the same way a beach ball wiggles beneath the palm of someone trying to hold it underwater, Letro said. It is so hard to nail down any storm's exact forward direction that scientists consider a prediction good if it places the storm within 50 miles of its actual track. Based on that gauge, forecasts for Fay were spot on.

But in determining whether to evacuate a coastline or issue hurricane warnings, a 50-mile error leaves a lot of uncertainty.

"The Hurricane Center did a very good job of forecasting Fay, but the problem is the devil is in the details," Letro said.

As a local forecaster, his job at the time was trying to get at those details to inform emergency management. "Really, when we get down to the bottom line, it's: 'What are the impacts going to be for me?' That's hard enough for a storm that's moving in a straight line."

While local forecasters and emergency workers are looking to Fay as a reminder that even tropical storms are volatile and dangerous, scientists at the National Hurricane Center are analyzing Fay's many quirks.

"For me, the most surprising thing was that it continued to intensify after it made landfall in South Florida," Beven said.

This story appeared in print on page A1


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