U.S. Avoids Major Landfall So Far in Active Hurricane Season

The 2010 Atlantic hurricane season has been very active in the number of storms but is likely to go down as a non-event for most people in the United States, which has so far dodged a major landfall, the top official U.S. hurricane forecaster said this week.

Before the June 1-Nov. 30 season got under way, residents of hurricane danger zones were warned by many forecasters they faced a very high probability of a major hurricane making landfall along the U.S. coastline.

That has not happened and with the most active part of the season winding down in the next two weeks or so, the chances of a major impact on the U.S. mainland or on energy interests in the Gulf of Mexico are ebbing.

“If you just use (U.S.) landfall as a criteria and did not pay attention to the numbers, you’d think this was a really quiet year,” U.S. National Hurricane Center director Bill Read told Reuters.

“A couple of relatively minor impacts and some flooding and that’s what we’d have to show for it,” he said.

Read said 2010 was still likely to go down in the record books as another in a string of exceptionally busy seasons, however. The United States had just been very lucky in not getting hit by a major hurricane.

Hurricane Earl, which became a Category 4 hurricane on the five-step Saffir-Simpson scale of storm intensity, came the closest by approaching to about 100 miles off North Carolina and southern New England last month, Read said.

“That’s a relatively narrow escape if you look at it from the global perspective,” he said.

Read also noted that the 2010 Atlantic season had taken a high toll in flood and mudslide deaths in Central America and Mexico, meanwhile.

An average season produces about 10 storms, of which six become hurricanes. This year has seen 15 named storms so far, with Otto forming as a subtropical storm over the Western Atlantic Wednesday, but posing no immediate threat to land.

U.S. oil and gas installations in the Gulf of Mexico have been virtually unscathed by this year’s hurricane season, which posed an early threat to efforts to control and clean up oil spewing from the ruptured Gulf of Mexico well owned by BP Plc, which was the worst oil spill in U.S. history.

Read said the eastern portion of the Gulf and the Caribbean, along with southern Florida, were not totally out of the woods yet, however.

With sea surface temperatures still very high, conditions for storm or hurricane formation, especially over the Caribbean, remain favorable, Read said.

Tropical cyclones draw energy from warm sea water.

Read expressed particular concern for impoverished and nearly treeless Haiti, saying it had just been “an amazing stroke of good fortune” that the earthquake-ravaged nation had not been hit by a major storm so far this year.

“They’re so vulnerable, it wouldn’t take much to cause a crisis,” he said.

LANDFALLS TOUGH TO PREDICT

Though forecasters have cut their errors in predicting the track of a hurricane, Read said there were still problems in terms of their long-term “skill” in pointing to landfalls.

In June, for instance, leading U.S. forecasters at Colorado State University had said the chance a major hurricane would make a landfall on the U.S. coastline this year was 76 percent compared with the last-century average of 52 percent.

But Read said it was not surprising no major hurricanes had hit the U.S. coast directly, given global oceanic and atmospheric conditions.

“It’s highly dependent on where they form and the steering currents at the time,” Read said, when asked about the ability to predict landfalls.

“With the weather pattern that was in place and the fact that these (storms) formed so far out to the east, it’s not surprising that they turned off to the north,” he said.

“As soon as you find a weakness in the big high, the Bermuda-Azores high, you’ll get that effect. That’s why Igor and Danielle and Julia among others went straight north pretty much.”

The weather pattern known as La Nina was also a factor behind this year’s hurricane season, since it brought wind conditions that foster Atlantic hurricanes.

La Nina is a cooling of the sea surface in the tropical Pacific and has had an impact on global weather. It tends to reduce the shearing winds that can disrupt nascent storms in the Atlantic.

“In the eastern Pacific this will be one of the quietest seasons on record,” Read said. “That’s what you see in a La Nina pattern, a lessening of storms in the Pacific and a greater chance of storms in the Atlantic.”

(Editing by Pascal Fletcher and Eric Walsh)