El Niño is suppressing Atlantic hurricane activity, Colorado State researchers say in updated forecast

Colorado State University researchers further reduced their projections for the number of named systems, including the odds of landfalls, during the remaining months of the Atlantic hurricane season.  

But they also advised people to stay prepared.

"We are forecasting a well below-average probability for major hurricane landfalls along the continental United States coastline and in the Caribbean," the researchers posted Wednesday. "As with all hurricane seasons, coastal residents are reminded that it only takes one hurricane making landfall to make it an active season."

In the update on their storm season, the research team cut its number of forecast storms from 9 to 7 before the season ends Nov. 30. The count includes two tropical systems that have already formed this year.

The forecast maintains the chance for four hurricanes to form, with one reaching Category 3 or greater status on the Saffir-Simpson Hurricane Wind Scale, where maximum winds are at least 111 mph.

The update is the third for the school since they initially forecast 13 named storms in April. The predicted storm count was lowered to 11 in June and 9 in July.

As with other forecasters that have downgraded their outlooks, the university researchers pointed to the effect of El Niño weather conditions suppressing tropical activity in the Atlantic.

"Sea surface temperatures across the Caribbean and tropical Atlantic are slightly above their long-term averages," the researchers posted online. "We anticipate the powerful El Niño being the dominant factor for the upcoming hurricane season, driving very high levels of tropical Atlantic vertical wind shear."

Last week, the meteorological company AccuWeather recently maintained its revised forecast for the nearly two-month-old hurricane season of 8- to 14-named storms of which four to seven will grow into hurricanes.

Before the season started on June 1, AccuWeather forecast between 11 and 16 named storms.

The season has so far seen two tropical storms, Arthur and Bertha, both of which affected parts of the nation's Gulf coast.