Atlantic hurricane activity is expected to be slightly below average this year, reflecting the likely development of El Nino conditions, the Colorado State University (CSU) says in its first forecast for the season.

The CSU Tropical Meteorology Project team predicts 13 named storms during the June 1-November 30 period, with six likely to become hurricanes and two to reach major hurricane strength.

That compares with an average 14.4 named storms across 1991-2020, with 7.2 hurricanes and 3.2 major hurricanes.

CSU says there’s more uncertainty than normal around the outlook given conflicting signals between a potentially robust Pacific Ocean El Nino and an anomalously warm tropical and subtropical Atlantic. If a robust El Niño doesn’t develop, the potential still exists for a busy season.

So far, the 2023 hurricane season is exhibiting characteristics similar to 1969, 2002, 2004, 2006, 2009, 2012, 2014 and 2015.

“Our analog seasons exhibited a wide range of outcomes, from below-normal seasons to hyperactive seasons,” Department of Atmospheric Science research scientist and lead author of the report Phil Klotzbach said. “This highlights the large uncertainty that exists with this outlook.”

The probability of a major hurricane making landfall is 44% for the entire US continental coastline and in the Caribbean, which compares to an average 43% for 1880-2020. For the Gulf Coast from the Florida panhandle westward to Brownsville Texas the probability is 28%.

The CSU team will issue forecast updates on June 1, July 6 and August 3.