RALEIGH, N.C.—Insured losses could reach $200 million from hundreds of tornadoes that struck 16 states in mid-April, hitting North Carolina the hardest during the three-day outbreak, experts say.

As insurers and emergency management personnel worked last week to assess total damage caused by the deadly storm system, meteorologists and catastrophe modelers forecast more turbulent weather ahead.

At least 45 people died during tornadoes and severe thunderstorms, which packed high winds, heavy rain and hail, that formed April 14 over Oklahoma and Texas and charged into the Southeast during the next two days.

The worst destruction, according to reports and ground observers, occurred April 16 in eastern North Carolina. State authorities confirmed that more than 440 homes and 21 businesses were destroyed by tornadoes or high winds.

The damage total is “a constantly moving target,” said a spokeswoman for the North Carolina's Raleigh-based Department of Crime Control and Public Safety. As of late last week, the death toll in the state had risen to 24, making the April 16 storm the deadliest to strike North Carolina in nearly 30 years. “We still have assessment teams trying to go through all the counties and figure it all out,” the spokeswoman said.

Multiple deaths and dozens of injuries also were recorded in Alabama, Arkansas, Oklahoma and Virginia. More than 320 homes and 30 businesses were destroyed or badly damaged in Mississippi.

In all, witnesses in 16 states reported 320 tornadoes during the three-day outbreak. However, a National Weather Service spokesman said the actual number of tornadoes is likely to be lower once storm reports are examined.

Total insured losses resulting from the storms are likely to exceed $100 million, according to Oakland, Calif.-based catastrophe modeler EQECAT Inc.

Dave Finnis, Atlanta-based executive vp and national property practice leader at Willis North America, said insured losses from the storms could reach as high as $200 million.

Oldwick, N.J.-based rating agency A.M. Best Co. Inc. said in a report that it expects “significant” insured losses resulting from the storms. In a statement, Boston-based catastrophe modeler AIR Worldwide Corp. also said it expects “significant” insured losses from the storms. Neither firm provided a damage estimate.

So far, 2011 has been “an extremely active year” for tornadoes, EQECAT said. “The convective storm activity to date in 2011 is about double the long-term average,” it said in a statement.

Typically, according to the New York-based Insurance Information Institute, about 1,200 tornadoes occur a year in the United States. Damage from convective storms—tornadoes, hail and straight winds—is estimated to exceed $6 billion a year, according to EQECAT.

The most active year on record was 2004, when more than 1,800 tornadoes occurred nationwide, according to the National Oceanic and Atmospheric Administration.

Among major North Carolina insurers in the mid-April storms, several hundred claims had been filed for commercial property damage.

Bloomington, Ill.-based State Farm Mutual Automobile Insurance Co. had received about 200 commercial claims as of late last week, but had already received more than 2,200 claims for damaged or destroyed residences and 1,250 claims for personal auto damage.

“This is a tough one, because tornado damage is usually only in one place,” said Kim Conyers, a State Farm public affairs specialist in Charlottesville, N.C. “This storm damage is all over the place, and that's made it really challenging to get information and to know where to deploy your resources.”

Erie Indemnity Co., which operates under Erie, Pa.-based Erie Insurance Group, also had received about 200 commercial claims. A company spokeswoman said it had received more than 100 new home, auto and commercial claims a day since the storms hit.

At the Raleigh-based North Carolina Farm Bureau Insurance Co., the state's largest local insurer, a senior claims executive said the company had received about 5,000 home and auto damage claims with estimated insured losses of $35 million. Steve Carroll, executive vp and general manager, said reinsurance will help protect the company's balance sheet.

“We've got a strong reinsurance program in place that helps us with severe catastrophe losses,” Mr. Carroll said. “This storm was well within our ability to handle” such losses.

As devastating as the mid-April storms were, it is only the start of the season for tornado-prone central and southern states.

National Weather Service meteorologist Greg Carbin said severe weather is all but assured as the tornado season moves toward its peak in late May or early June.

“You only hope people can get up and recover from this, because there will be other storms on the way,” Mr. Carbin said.