Colorado State lowers Atlantic hurricane forecast, expects well below-normal season

Colorado State University has lowered its forecast for the Atlantic hurricane season and now expects well below-normal activity, citing a strengthening El Niño that is likely to suppress storm formation during the peak of the season.

The updated forecast released on Wednesday calls for 9 named storms, including 4 hurricanes and 1 major hurricane. That is down from Colorado State’s April forecast of 13 named storms and its June forecast of 11 named storms.

Only one named storm has formed so far this season. Tropical Storm Arthur brought heavy flooding to Texas, Louisiana, Mississippi, Alabama and Georgia in June.

Forecasters said moderate El Niño conditions are likely to intensify over the next few months, with a strong El Niño possible during the peak of hurricane season. Colorado State said that would likely produce high levels of vertical wind shear across the tropical Atlantic and Caribbean, limiting hurricane development.

Sea surface temperatures across the Caribbean and tropical Atlantic are near their long-term averages, according to the forecast. Colorado State said overall Atlantic storm activity, measured by accumulated cyclone energy, is expected to be about 40% to 45% of its long-term average.

The National Oceanic and Atmospheric Administration (NOAA) is also predicting a below-normal Atlantic hurricane season, with 8 to 14 named storms, including 3 to 6 hurricanes and 1 to 3 major hurricanes.

Colorado State said the probability of at least one major hurricane making landfall along the continental U.S. coast after July 7 is 17%, compared with a long-term average of 43%. The probability is 8% for the U.S. East Coast, including Florida, and 10% for the Gulf Coast.

The probability of at least one major hurricane tracking through the Caribbean is 19%, compared with a long-term average of 47%.

Forecasters cautioned that a quiet season can still be destructive if a storm hits land. “It only takes one hurricane making landfall to make it an active season,” the report said.