NOAA's Christopher Landsea warns HURDAT2, used by insurers, isn't fully accurate back to 1850s

HURDAT2, the hurricane database insurers use to estimate risk, is not a fully accurate record back to the 1850s, Christopher Landsea told ILS Convergence 2026, according to Royal Gazette Bermuda Re. "If you are making assumptions that we have a 100 per cent complete, accurate database back to the 1850s, you are mistaken," Landsea, a meteorologist at NOAA's National Hurricane Centre, said. He cited "a lot of technological influences" and "a lot of warts in it because it is not perfect."

A September 21, 1922 hurricane that passed over Bermuda, killing a sailor and a child, was downgraded from category 4 to category 3 in 2009 after Landsea's reanalysis of reports from the 1920s. That left it the fourth strongest storm to hit Bermuda. His team also upgraded Hurricane Andrew from category 4 to category 5 a decade after it struck Florida in August 1992; that change, the report said, altered how rare a comparable southeast Florida landfall appeared to be.

Landsea said the Atlantic Hurricane Database Reanalysis Project uncovers roughly three to five new historic storms a year. One was a 1970 North Atlantic storm with a ragged eye that lasted two days, added to the database on the strength of that observation and reports from a couple of ships. For ILS investors modelling long-tail catastrophe risk, the historical baseline is still being revised.