NOAA forecasts 'above-normal' hurricane season

Agency expecting 12 to 18 named storms

May 19, 2011|By Frank D. Roylance, The Baltimore Sun

The federal government's hurricane forecasters urged Americans living in vulnerable coastal regions to prepare for another "above-normal" Atlantic hurricane season. But they acknowledged that scientists still can't predict before the season begins where the storms are most likely to strike.

"We are actively working on trying to address the question … about predicting landfalls. It's something we think, with additional research, that we can work on," said NOAA Administrator Jane Lubchenco.

Once storms form and move toward land, the National Hurricane Center is quite good at predicting where they are most likely to make landfall, forecasters say.

For now, Lubchenco said, that pre-season uncertainty only "underscores the importance of everyone having a plan and everyone being prepared."

Landfalls in Maryland are rare. The state is far more likely to be brushed by a storm passing just off the coast, or swamped by one weakened after landfall in the Carolinas.

These include Gloria, which whirled by just offshore in 1985, dropped 6 inches of rain at BWI, eroded beaches at Ocean City and forced to town's evacuation; and Isabel in 2003, which struck in the Carolinas before sending a disastrous storm surge up the Chesapeake.

The 2011 Atlantic hurricane season opens formally on June 1 and continues through November. The National Oceanic and Atmospheric Administration's forecast calls for more storms than have been predicted by others, including, WeatherBug and Colorado State University.

NOAA forecasters are expecting 12 to 18 named storms, of which six to 10 will become hurricanes, with top sustained winds of 74 mph or more.

Of those hurricanes, NOAA expects three to six will reach Category 3 or higher, with top winds of 111 mph or more.

The long-term averages for a single season at 9.6 named storms, with 5.9 hurricanes and 2.3 reaching Category 3.

Like the other hurricane forecasters this spring, the NOAA team at the Climate Prediction Center bases its expectations for the coming storm season, in part, on a multidecade cycle of heightened activity in the Atlantic that began in 1995.

In addition, Lubchenco said, "ocean water remains warmer than average across the tropical Atlantic." The temperatures are about 2 degrees Fahrenheit higher than the long-term average. That's down from 4 degrees above average last summer, but forecasters still expect it to support above-normal storm development.

Another factor in the forecast is the continuing La Nina conditions in the tropical Pacific Ocean. La Nina is a time of below-average sea-surface temperatures in the tropical Pacific. It tends to suppress the Atlantic wind shear that would put the brakes on hurricane formation.

"Though [La Nina conditions] are expected to weaken," Lubchenco said, "reduced wind shear is expected to continue at least into early summer."

Forecasters don't think the 2011 Atlantic hurricane season will approach the 19 named storms that formed last year. That was the third-most-active season on record, but none of the 12 storms that reached hurricane strength made landfall on U.S shores.

"The U.S. was lucky last year," she said. "We cannot count on having the same luck this year. It is vitally important that people prepare."

FEMA Director Craig Fugate said his forecast is that "many people will not be prepared, and will try to get ready at the last minute … and will not have enough time."

"Now is the time, if you haven't already, to get your plan together for what you and your family would do if disaster strikes," he said.

Federal, state and local emergency response services are ready to help when disaster strikes. But "we cannot and should not make the most vulnerable members of the community get in line behind those who have not prepared."

For more on disaster planning, visit

Maryland weather blog: Frank Roylance on meteorology

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