* Top forecasters increase Atlantic hurricanes prediction
* See 18 named storms, 10 hurricanes, five of them major
* CSU team gives 76 pct probability of major U.S. landfall
* Hurricanes could drive spilled oil onto Gulf coast (Recasts, adds quotes, details)
By Pascal Fletcher
MIAMI, June 2 (Reuters) - The 2010 Atlantic hurricane season will be even more active than feared, leading U.S. forecasters said on Wednesday as they predicted 10 hurricanes, five of them major, with a 76 percent likelihood that a major hurricane would hit the U.S. coastline.
The outlook from the Colorado State University team follows predictions by U.S. government scientists for an intense season that could disrupt efforts to contain a huge Gulf of Mexico oil spill and also batter earthquake-ravaged Haiti.
Increasing a previous estimate for a “very active” season, the leading CSU storm research team founded by hurricane forecast pioneer William Gray said the six-month season beginning on June 1 would likely see 18 named tropical storms.
Of these, CSU saw 10 becoming hurricanes, with five becoming major Category 3 or higher hurricanes with winds above 110 miles per hour (177 km per hour).
The CSU scientists increased their forecast from an April 7 prediction of 15 named storms, eight hurricanes and four major hurricanes.
“The probability of a major hurricane making landfall along the U.S. coastline is 76 percent compared with the last-century average of 52 percent,” said forecaster Phil Klotzbach, who works with Gray.
The CSU team saw a 51 percent chance that a major hurricane would make landfall on the U.S. East Coast, including the Florida Peninsula, and a 51 percent chance that one would hit the Gulf Coast, from the Florida Panhandle to Brownsville, Texas.
It put the chance of a major hurricane tracking into the Caribbean at 65 percent.
The expected extreme hurricane season this year is seen posing a threat to efforts to control and clean up oil spewing from a ruptured Gulf of Mexico well owned by BP Plc (BP.L), described by President Barack Obama’s administration as the worst environmental disaster in U.S. history.
Experts warn that a storm surge in the Gulf of Mexico -- an abnormal rise in sea level created by a hurricane -- could whip the oil slick and chemicals used in trying to disperse it out of the Gulf and ashore on beaches, vegetation and even homes.
“If the storm tracks to the west of the oil, there is the potential that the counter-clockwise circulation of the hurricane could drive some of the oil further toward the U.S. Gulf Coast,” Klotzbach said.
But he added the forecasters did not see the huge, fragmented oil slick itself having much of an impact on any tropical storm or hurricane passing over the area.
There are fears too about how a major hurricane sweeping through the Caribbean over Haiti would affect around 1.5 million homeless survivors of the Jan. 12 earthquake who are camping out in the streets under tents and tarpaulins.
Quake survivors living in the makeshift camps are seen as highly vulnerable to the tropical rains, flooding and landslides which have killed thousands of Haitians in the past.
Detailing weather conditions seen favoring the formation of hurricanes, Gray said the CSU team increased its forecast “due to a combination of a transition from El Nino to current neutral conditions and the continuation of unusually warm tropical Atlantic sea surface temperatures.”
Warmer waters contribute to the development of hurricanes and dissipation of the El Nino weather phenomenon over the Pacific Ocean reduces the probability of wind shear -- caused by a clash between prevailing upper-levels winds out of the west and lower-level easterly winds out of Africa -- that can tear apart hurricanes or break up their circulation.
The National Oceanic and Atmospheric Administration last week predicted one of the more active hurricane seasons on record, forecasting 14 to 23 named storms, with eight to 14 becoming hurricanes, nearly matching 2005’s record of 15.
The Gulf Coast may see a repeat of the 2005 season when a record 28 storms formed, which killed nearly 4,000 people and caused an estimated $130 billion in damages. The list included Hurricane Katrina, which devastated New Orleans. (Editing by Tom Brown and Mohammad Zargham)