• Why so many US states are at such a higher risk of a hurricane strike this year.

Warmer than average temperatures expected

Texas and Louisiana may have braced for the worst this week as backto-back hurricanes Marco and Laura barreled toward them, but in this record-setting Atlantic hurricane season, almost every coastal U.S. state east of the Mississippi River should also be on high alert.

All but one of the 18 states bordering the Atlantic Ocean or Gulf of Mexico face a greater risk this year of a hurricane strike, according to the forecast from Colorado State University’s Department of Atmospheric Science, which has issued seasonal hurricane forecasts every year since 1984.

Only New Hampshire’s risk remains unchanged at a 1% chance of a direct hit. Every other state’s risk increased by 33%-100%.

Delaware, Maine and Maryland all saw their odds double this year, but their overall threat remains low compared to states like Florida, Louisiana and Texas.

Blame the increased risks on warmer-than-average sea surface temperatures, weaker tropical Atlantic trade winds and a reduced vertical wind shear that would otherwise help to break up tropical storms before they can strengthen. Those conditions have made 2020 a record-setter. This is the first year that more than a half dozen storms have made landfall before September, said Phil Klotzbach, lead forecaster of the Colorado State University meteorology team.

On Thursday, the National Hurricane Center was watching two potential systems in the Atlantic for possible development.

La Niña looms

The hyperactive season is forecast to continue in the weeks ahead as a pattern of cooler-than-normal sea surface temperatures called La Niña continues to develop along the equator in the Pacific Ocean.

“That increases the likelihood of an extremely active Atlantic hurricane season,” said Gerry Bell, a research meteorologist and lead seasonal forecaster for the National Oceanic and Atmospheric Administration.

La Niña also points to an increased risk for landfalling hurricanes along the U.S. coast, Klotzbach said.

Given the dire forecast and the impacts of the coronavirus pandemic, meteorologists, emergency management officials and others worry about how millions of coastal residents will make decisions this year regarding evacuations and sheltering when a hurricane approaches. They say it’s especially important this year to know your risks and plan ahead.

“Every hurricane season I’m concerned so many people live on the coast who have never been through a tropical storm or hurricane,” said Alan Sealls, chief meteorologist at NBC 15 in Mobile, Alabama. “We’ve had huge population growth along the coastline.”

As Laura approached the northern Gulf Coast, forecasters at the National Hurricane Center warned of a potential storm surge as high as 13 feet. The destructive force of storm surge is the leading reason why barrier islands and low-lying areas are evacuated before a hurricane.

In a Category 1 hurricane, more than 800,000 homes are at risk of storm surge in the coastal regions along the Gulf and Atlantic, according to the Insurance Information Institute. Many more are at risk when a storm grows more intense, with 6.1 million homes at risk of storm surge from a Category 4 hurricane, with sustained winds at 130 mph or more.

This year, emergency management officials throughout the country have had to make adjustments to planning to account for the coronavirus, Sealls said.

“Shelters are going to have lower capacity and that means a lot of people are going to be jammed up about whether they go and what they can do.”