What Happened To The Big Storms?

Hurricane Helene was downgraded to a Category 1 storm early Thursday as it churned in the open Atlantic, the latest indication that what was supposed to be another brutal hurricane season has instead been surprisingly mild.

Forecasters say one big reason the U.S. has been spared so far is a low-pressure system off the East Coast that has been a shield against which storms just bounce off.

Still, forecasters warned that there are two months left in the season, and September and October are typically among the busiest months.

Two main factors have contributed to the coastline calm: A high-pressure system in the Atlantic known as the Bermuda High last year was centered close to Bermuda, but now is positioned hundreds of miles to the east. That, in turn, has made room for a low-pressure system to develop in the Atlantic between the Carolinas and Bermuda.

"Instead of high pressure pushing hurricanes toward the United States there has been low pressure that repels hurricanes," said Lixion Avila, a forecaster at the National Hurricane Center.

Unlike a high-pressure system's clockwise swirling, the low pressure circulates counterclockwise and is associated with winds that help push storms to the north and northeast. It has been in place since late August and played a role in keeping Hurricanes Florence, Gordon and Helene away from American shores.

Beyond that, though, Pennsylvania State University meteorologist Paul Knight said that the season has simply not been as frenzied as last year. And fewer Atlantic storms mean fewer chances one will actually strike the United States.

Last year was the busiest Atlantic season on record, with 28 named storms, 17 of which had already formed by this point. Two hurricanes — Dennis and Katrina — had already struck by this time last year, and Rita hit on Sept. 24.

This year, forecasters originally estimated up to 16 named storms and later trimmed their projection by one. There have been eight named storms so far. Tropical Storms Alberto and Ernesto hit Florida this year, but did little damage.

Federal scientists have said that weak El Nino conditions this year have also inhibited hurricane development by increasing crosswinds over the Caribbean. The winds can rip storms apart or stop them from forming.

Still, forecasters warned that the Bermuda High could move closer to shore, or the low-pressure system could weaken before the end of the season, which runs from June 1 to Nov. 30.

"Don't be fooled by anybody that they know what's going to happen in two weeks," Avila said. "We don't know if this pattern is going to go or stay."

Knight said most of the East Coast, from the Outer Banks of North Carolina to Maine, should be safe from a hurricane this year. But Florida, hit hard by the previous two hurricane seasons, is a different story.

"You're really never safe until late November," Knight said.

Meanwhile, the season's latest hurricane, Helene was downgraded to a Category 1 storm early Thursday, as it remained in the open Atlantic, well east of Bermuda.

At 5 a.m. EDT, Helene was centered about 550 miles east-southeast of Bermuda and was moving toward the north near 13 mph, according to the National Hurricane Center in Miami. Maximum sustained winds were near 90 mph, down from 100 Wednesday night.

Hurricane force winds extended outward up to 45 miles.

"Although Helene is expected to pass several hundred miles to the east of Bermuda, large ocean swells producing hazardous surf conditions could affect the area later today and on Friday," said Stacy Stewart, a senior hurricane specialist.