Losses from Hurricane Debby, which crossed the Florida coast before bringing flooding to southern US states, will mostly be borne by primary insurers, Moody’s Ratings says.

Debby brought hurricane-force winds, a damaging storm surge and heavy rainfall to parts of Florida’s Big Bend region and Gulf coast after sweeping ashore at category 1 strength about 7am last Monday (local time) near the small community of Steinhatchee.

“We expect a majority of insured losses from Hurricane Debby to fall within primary insurers’ retentions under their reinsurance coverages,” Moody’s Ratings VP and senior credit officer for the financial institutions group James Eck said.

“In general, primary insurers are retaining more risk this hurricane season as attachment points ... have moved higher over the past few years, with primary companies taking on more of the loss burden from reinsurers for small to mid-size catastrophe events.”

Debby also brought flooding to Georgia and made landfall a second time – as a tropical storm – in South Carolina early on Thursday (local time), before moving north. Tornadoes also formed as a result of Debby.

Media reported that Gallagher Re considered Debby a “very manageable” event for the insurance and reinsurance sectors, and wind and water-related insured losses could total $US1-$US2 billion ($1.5-$3 billion) based on preliminary estimates.

The Insurance Information Institute said Debby was the fourth named storm of the Atlantic hurricane season and the second to make landfall after Beryl, which struck Texas on July 8.

Colorado State University hurricane researchers continue to expect an “extremely active” hurricane season, with an updated August forecast predicting 23 named storms, 12 hurricanes and six major hurricanes.

The National Hurricane Centre is currently monitoring a potential cyclone and has issued tropical storm watches for areas including Guadeloupe, St Kitts and Antigua. The “disturbance” is expected to move across portions of the Leeward Islands on Tuesday and approach the US and British Virgin Islands on Tuesday night (local time), it says.