Isaias strengthened overnight into the first hurricane of the 2026 Atlantic season, and the reinsurance market has already put a rough price on it. If it comes ashore at Category 1 or 2 strength, insured losses should run into the low to mid-single-digit billions of dollars, the reinsurance broker Gallagher Re said in commentary reported on Thursday. The economic cost, it said, would probably be a few billion dollars higher.

The gap between those two numbers is mostly water.

In its advisory number 8, issued at 10 a.m. Central time on Thursday, the National Hurricane Center put the storm's maximum sustained winds near 85 miles an hour, with its centre about 380 miles south of the mouth of the Mississippi River and moving east-northeast at 10 mph, according to its advisory. It expects further strengthening through early Friday and landfall on the northern Gulf Coast late Friday or early Saturday. A hurricane warning runs from Ocean Springs, Mississippi, to the line between Bay and Gulf counties in Florida. The centre's forecast has winds peaking at 95 knots, about 110 mph, on Friday before easing slightly as the storm nears the coast. Its next full advisory is due at 4 p.m. Central time.