FAIRHOPE, Ala. — Forecasters have released their latest predictions for the 2009 Atlantic Hurricane Season. Colorado State University researchers and NOAA scientists both lowered their tropical outlook this week because El Niño conditions are expected to intensify over the next few months. The phenomenon is indicated by warmer than normal waters along the equatorial central and eastern Pacific Ocean.

CSU researchers are now anticipating only 10 named storms forming in the Atlantic basin between now and Nov. 30, the official end of the current hurricane season. Four of the storms are expected to become hurricanes, and of those, two are predicted to develop into major hurricanes (Saffir/Simpson Scale category 3, 4 or 5) with sustained winds of 111 mph or more.

Back in June, the CSU team was projecting 11 named storms, five hurricanes and two major hurricanes. Long-term averages, according to CSU, are 9.6 named storms, 5.9 hurricanes and 2.3 major hurricanes each year.

“We had El Niño developing in the tropical Pacific. It increases vertical wind shear in the Atlantic,” said Dr. Phil Klotzbach, CSU research scientist and lead author of the report issued Tuesday. “That disrupts the circulation (of a tropical system). It tilts the vortex.”

NOAA’s Climate Prediction Center, a division of the National Weather Service, on Thursday issued their own predictions, calling for a 50 percent probability of a near-normal season, a 40 percent chance of a below-normal season and a 10 percent probability of an above-normal season.

NOAA forecasters say there is a 70 percent chance of seven to 11 named storms, of which three to six could become hurricanes, including one to two major hurricanes.

That represents a change from the federal agency’s May forecast with an increased probability of a below-normal season and an expectation of fewer named storms. The earlier outlook called for nine to 14 named storms, of which four to seven could become hurricanes, including one to three major hurricanes.

According to NOAA statistics, there are 11 named storms during an average hurricane season, of which six become hurricanes and two of those become major hurricanes.

Dr. Gerry Bell, lead seasonal hurricane forecaster at the Climate Prediction Center, concurs with Klotzbach on the cause of what could be a mild season. He said, “El Niño continues to develop and is already affecting upper-level atmospheric pressure and winds across the global tropics. El Niño produces stronger upper-level westerly winds over the Caribbean Sea and tropical Atlantic Ocean, which help to reduce hurricane activity by blowing away the tops of growing thunderstorm clouds that would normally lead to tropical storms.”

Although that’s good news for those of us still stinging from hurricanes such as Ivan in 2004 and Katrina in 2005, this does not mean it’s time to let your guard down.

Hurricanes can indeed strike during an El Niño. Among the clear examples are Betsy in 1965, Camille in 1969, Bob in 1991, Danny in 1997 and Lili in 2002.

Even the slow start of the 2009 season is no reason to breathe easier.

Klotzbach said Hurricane Andrew, the first storm of the 1992 season, didn’t form until August and it devastated south Florida as a powerful Category 5 storm. Likewise, only one storm had developed prior to September 1961, he added, and then four major storms formed that month.

“Every one has their own personality,” Klotzbach said, referring to El Niño, hurricanes and individual seasons. “You get El Niños in active eras (such as the multi-decadal signal that began in 1995) and inactive eras. When we’re in active eras, El Niños are typically shorter lived.”

Klotzbach expects the existing El Niño to remain into the winter months because it formed so early, however. He said the systems are a way nature transfers energy between the Eastern and Western hemispheres.

Meanwhile, Atlantic sea surface temperatures slightly increased in recent months, and there is greater rainfall over west Africa. Both are conditions that promote storm development, making the formation of an El Niño somewhat less effective than it might have otherwise been.

“That’s why we didn’t greatly reduce our forecast,” Klotzbach said.

Federal Emergency Management Agency Administrator Craig Fugate said, “These outlooks are extremely valuable when determining cycles and trends for the season, however, they don’t tell us when the next storm will occur or where it may strike. It only takes one storm to put a community at risk. That is why we need to take action and prepare ourselves and our families before the next storm hits, including developing a family disaster plan. By taking a few simple steps now we can help ensure that we are better prepared and that our first responders are able to focus on our most vulnerable citizens.”

NOAA pointed out that predicting where and when a storm may hit land depends on the weather conditions in place at the time the storm approaches. Therefore the agency’s long-term forecasts do not include landfall projections.

CSU does issue landfall probabilities though, which are calculated based on 20th century landfall statistics and then adjusted by the latest seasonal forecast. The researchers suggest that the probability of a major hurricane making landfall along the U.S. coastline is 46 percent, compared with the last-century average of 52 percent.

For the Gulf Coast, from the Florida panhandle westward to Brownsville, Texas, the CSU team says there is a 26 percent chance that a major hurricane will make landfall here (the long-term average is 30 percent).

Currently observed climate factors are similar to conditions that occurred during the 1957, 1963, 1965 and 2002 seasons. The average of these four seasons had slightly below-average activity, and Klotzbach and his mentor and colleague, Dr. William Gray, predict the 2009 season will have activity in line with the average of those five years.

The pair advise coastal residents not to change their hurricane preparedness plans because despite the trends studied, major hurricanes are still a possibility.