FAIRHOPE, Ala. — Conditions favoring a resurgence in tropical storms and hurricanes this year continue to develop, and on Wednesday forecasters at Colorado State University increased the number of storms they predict could impact the region during the 2010 Atlantic Hurricane Season.

“It’s looking like a pretty active season,” said Dr. Phil Klotzbach, lead CSU forecaster. Referring to the oil spill in the Gulf of Mexico, he added, “There are a lot of questions about what will happen, especially if a hurricane tracks to the west of you.” He indicated the counterclockwise storm circulation could push more of the oil toward the shore.

CSU meteorologists are now calling for 18 named storms during the season, which began Tuesday and will end Nov. 30. Of those storms, the team anticipates 10 hurricanes, with five expected to develop into major hurricanes (Saffir/Simpson Scale category 3, 4 or 5) with sustained winds of 111 mph or more.

The forecast was based on much warmer-than-normal tropical Atlantic sea surface temperatures and cooling tropical Pacific conditions that will likely transition into mild La Niña conditions by midseason.

Klotzbach said, “El Niño has essentially gone away — it’s officially neutral. We could have a weak La Niña by August or September, and there would be less vertical (wind) shear in the Atlantic.”

The lack of wind shear to hamper the development of storms, combined with atmospheric and sea surface conditions that favor tropical systems, could spell trouble for the Gulf Coast. The scenario harkens back to the very busy 2005 season.

“There are a lot of similarities,” Klotzbach said. “We’re not necessarily forecasting a record season like that year, but we are predicting an active season.”

The scientists bumped up their forecast from April’s prediction of 15 named storms, eight hurricanes and four major hurricanes. Long-term (1950-2000) averages are 9.6 named storms, 5.9 hurricanes and 2.3 major hurricanes per year.

Klotzbach said, “Some years you get a lot of weak storms, but other years (like 2004, when Hurricane Ike devastated the Florida panhandle) you get a few storms that are long-lived, strong hurricanes.”

He noted coastal Alabama avoided the bulk of Ike’s catastrophic damage because the state was, for the most part, on the western side of the storm. Even though Hurricane Katrina was further away geographically than Ike, the 2005 storm showed us its more powerful eastern edge.

The CSU team also updated its U.S. landfall probabilities, which are calculated based on historical landfall statistics and then adjusted by the latest seasonal forecast.

“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,” Klotzbach said. “We expect that the current trend from El Niño to neutral conditions will persist, and that weak La Niña conditions will develop.

According to the the CSU forecast team, there is a 51 percent chance that a major hurricane will make landfall on the U.S. East Coast, including the Florida peninsula (the long-term average is 31 percent). There is also a 51 percent chance that a major hurricane will make landfall on the Gulf Coast this year, from the Florida panhandle westward to Brownsville, Texas (the long-term average is 30 percent).

“We really don’t think the oil will impact the storm,” Klotzbach said. “It will churn up the sea surface, and will have some impact on where the oil goes.”

He pointed out that a 30-40 mph sustained wind would mix up the oil on the surface, likely eliminating whatever direct impact it might have had on the storm. Klotzbach acknowledged that the hurricane season, if it unfolds as predicted, could have an impact on spill cleanup.

“It could be a messy storm surge at the end of the day he said,” adding that much depends on when BP successfully caps the well permanently. “If you have a major hurricane in the Gulf of Mexico, it’s a major concern in and of itself, but the oil will make things worse.”

Currently observed climate factors are similar to conditions that occurred during the 1958, 1966, 1969 and 2005 seasons. The average of these four seasons had well above-average activity, and Klotzbach and forecast co-author William Gray predict the 2010 season will have activity in line with the average of those four years.

The hurricane forecast team predicts tropical cyclone activity in 2010 will be 195 percent of the average season. By comparison, last year’s tropical cyclone activity that was about 69 percent of the average season.

The team will issue a final seasonal forecast update on Aug. 4.