What Helene and Milton showed about roofs, from the Gulf coast to the mountains

Helene: a Category 4 that kept moving

According to the NHC report on Helene, the hurricane made landfall about 10 nautical miles southwest of Perry, Florida, around 0310 UTC on September 27, 2024, as a Category 4. The report calls it the strongest landfalling hurricane in the Florida Big Bend since reliable records began around 1900.

Speed is what set Helene apart. NHC measured a forward motion of 27 knots at landfall and says that, as a result, Helene's strong winds, especially its gusts, penetrated far inland. Surface and radar data show it was still a hurricane over southern Georgia, and it did not become post-tropical until it reached southern Kentucky.

The report adds a detail that matters for roofs: Helene's gust factor ran 1.5 to 2.0, meaning its gusts were much stronger relative to its sustained winds than is typical. Weather Service ground surveys suggested gusts likely exceeded 70 knots across a wide area from the Florida Panhandle through eastern Georgia into central and western South Carolina, and tree and structural damage suggested gusts may have topped 90 knots in places. In the Florida counties under Helene's eastern eyewall, emergency managers reported that the majority of structures were damaged.

Lesson one: the tree next to the house is part of the roof

Helene's winds caused 65 direct deaths, which NHC says is the most direct wind deaths from any tropical cyclone in the continental United States going back to at least 1963. Falling trees caused 61 of them, and the largest numbers were in Georgia and South Carolina, far from where Helene came ashore.

Milton repeated the pattern on a smaller scale; its NHC report attributes four of its direct deaths in Florida to falling trees. IBHS lists trimming trees and branches near the roof among its pre-season steps to reduce wind and impact damage.

Lesson two: inland rain tests every weak point

Helene's rain did its worst far from the Gulf. NHC reports widespread totals of 5 to 10 inches from the Florida Panhandle across Georgia into the western Carolinas and southwestern Virginia, and a peak of 30.78 inches at Busick, North Carolina. Historic totals in the southern Appalachians produced catastrophic flooding and widespread landslides, and freshwater flooding caused at least 94 of Helene's direct deaths.

Flooding is not a roofing problem, but wind-driven rain is. IBHS warns that aging asphalt shingles can fail at wind speeds far below hurricane force, letting wind-driven rain into the home, and it recommends clearing gutters and downspouts so heavy rain drains away from the house.

Lesson three: no roof stops storm surge

At the coast, water was the destroyer. NHC estimates Helene's peak surge at 12 to 16 feet above ground level between Keaton Beach and Steinhatchee, where it destroyed about 80 percent of the buildings. In Yankeetown, the report notes, 20 people were rescued from their rooftops. Ready.gov states that storm surge has historically been the leading cause of hurricane-related deaths in the United States, and it tells anyone in a mandatory evacuation zone to leave immediately when local officials say so.

Milton: rapid strengthening, then tornadoes

The Milton report describes one of the strongest Atlantic hurricanes on record, peaking at an estimated 155 knots and 895 millibars over the Gulf. It weakened before making landfall on Siesta Key at 0030 UTC on October 10, 2024, as a Category 3 with maximum sustained winds near 100 knots. The strongest sustained wind reported in Florida was 79 knots, with a 93-knot gust, at a University of Florida tower at Venice Beach.

Milton's rain fell across the middle of the peninsula, with a maximum of 20.40 inches near St. Petersburg and record crests on the Hillsborough River. On October 9, the storm produced 45 known tornadoes on land in southern and central Florida, including three rated EF-3; NHC says Milton was the first tropical cyclone in SPC's tornado database, which begins in 1995, to produce more than one EF-3.

One roof became the storm's symbol. High winds ripped the fabric roof off Tropicana Field in St. Petersburg, and rain then fell into the stadium. NHC notes that the coast Milton hit hardest had been struck by Helene two weeks earlier, which complicated damage assessments, and it cites an NCEI estimate of $34.3 billion in U.S. damage.

Lesson four: the ladder is dangerous after the storm, too

Milton's report counts 27 indirect deaths in Florida, and 10 of them were falls related to storm preparations, clean-up or power failures. Helene's report lists incidents during post-storm cleanup among the causes of its indirect deaths. A damaged roof is a job for a roofer with fall protection, not for a homeowner on a wet ladder.

When you are ready to hire, the National Roofing Directory's find-a-roofer pages list contractors by state, and its encyclopedia explains why roof claims get denied so you can avoid the common problems. Ready.gov advises documenting property damage with photographs and contacting your insurance company.

Frequently asked questions

Why did Helene damage roofs so far from the coast?

The NHC report links it to Helene's fast forward motion and large size, which carried hurricane-force gusts far inland, and to an unusually large gust factor.

How strong was Milton when it made landfall?

A Category 3, with maximum sustained winds near 100 knots, when its center reached Siesta Key on October 10, 2024, according to the NHC report.

Did Milton cause tornadoes?

Yes. NHC counts 45 known tornadoes on land in Florida on October 9, 2024, including three EF-3s, one of which killed six people near Fort Pierce and Vero Beach.

Where can I read the official reports?

Both are posted by the National Hurricane Center: the Helene report and the Milton report.