More than a week since Hurricane Harvey struck Houston and the surrounding Texas and Louisiana coastlines, catastrophe modeling firms and others continue to issue estimates for economic and insured losses from the storm and its aftermath. It could be some time, however, before truly accurate numbers are in play for both categories.

“It takes months to get all the information,” Loretta Worters, vice president, Media Relations for the Insurance Information Institute, told Carrier Management.

Many expects the final numbers for economic losses, at least, to reach historic levels. The Insurance Information Institute said that the flood damage could rival costs create by Hurricane Katrina in 2005, which was the U.S.’s most expensive natural disaster until now. But a large amount of flood losses now, as then and with Hurricane Sandy, may have to be covered by the struggling National Flood Insurance Program. Adding to the uncertainty, claims adjusters only now are making their way through damaged homes and businesses as flood waters recede.

Also, CoreLogic estimate suggested that just over half of residential and commercial properties in metro Houston probably lack flood insurance coverage. CoreLogic calculates that as much as 70 percent of Hurricane Harvey flood damage isn’t covered by insurance. Insured losses in many cases will be covered by the federal government rather than private insurers once loss details can be better established.

“Harvey isn’t unprecedented,” Worters said on Aug. 31, when many claims adjusters still weren’t allowed in flooded areas. “Much like [Hurricanes] Katrina and Sandy, as soon as they are allowed in, they will start with the most devastated parts of the state” and take it from there over the coming weeks.

Preliminary Estimates Run the Gamut

That means for now, catastrophe modelers and other experts who evaluate storm damage continue to issue preliminary estimates.

Karen Clark & Company estimated total insured losses from Harvey would reach $15.4 billion, excluding the National Flood Insurance Program, in a brief issued on Sept. 1. KCC said that inland flooding insured losses will hit $12.4 billion, with $500 million coming from storm surge and another $2.5 billion coming from wind damage. Harvey first made landfall on Aug. 25.

CoreLogic’s Aug. 31 estimate put insured flood losses for homes in the 70-county area in Texas and Louisiana affected by the storm at between $6.5 billion and $9.5 billion, though it adds $1 billion to $2 billion more for wind damage.

At the same time, CoreLogic said uninsured flood losses for the same region should climb to between $18 billion and $27 billion.

AccuWeather, an American media company that provides commercial weather forecasting services, predicted total losses from Harvey will reach $190 billion, or 1 percent of the United State’s GDP. The number, released at the end of August, drew global attention, but it encompasses a wide amount of separate data points. AccuWeather President and Founder Joel Myers said the number includes insured losses, uninsured losses, and factors such as earnings by businesses, lost jobs and salaries, higher consumer costs due to gasoline and heating oil price hikes and crop losses in affected areas. (AccuWeather did not break out insured losses).

Catastrophe modeling firm RMS determined that economic losses from wind, storm surge and Harvey-related inland flood could hit as high as $70 billion to $90 billion, according to its late-August estimate. The firm said that Harvey losses with the National Flood Insurance Program are now estimated to reach $7 billion to $10 billion. (RMS insured loss estimates remain pending.)

AIR Worldwide predicted on Sept. 5 that insured losses from Hurricane Harvey’s wind, flood and storm surge will exceed $10 billion. Overall, the firm said that property losses stemming from flooding caused by Harvey’s record rainfall will hit between $65 billion and $75 billion.

*This story has been updated with new insured and economic loss damage estimates from AIR Worldwide.