- Hurricane Ida has made landfall on Cuba’s Isle of Youth.
- Next, it’s expected to rapidly strengthen over the Gulf of Mexico, then strike Louisiana and Mississippi as a Category 3 storm on Sunday.
- Climate change is causing more storms to strengthen rapidly like this.
Hurricane Ida is gaining strength in warm Caribbean waters as it barrels over Cuba’s Isle of Youth and toward the Gulf Coast.
Ida was a tropical storm early on Friday, but new data from storm-hunting aircraft indicate that it has reached hurricane strength. As of 1:45 p.m. ET, the storm had made landfall on the Isle of Youth. It’s moving northwest, towards western Cuba, at 15 mph with 75 mph winds.
Forecasters at the National Hurricane Center expect Ida to churn itself into a major hurricane before hitting Louisiana and Mississippi on Sunday. It’s expected to make landfall as a Category 3 storm with winds of 120 mph.
In response, the city of New Orleans has issued a mandatory evacuation order for all areas outside its levee system. The Friday announcement included voluntary evacuations for the rest of the city.
Cuba has issued a hurricane warning for its Pinar del Rio and Artemisa provinces. Up to 20 inches of rainfall from the storm may cause dangerous flash floods and mudslides across western Cuba, Jamaica, and the Cayman Islands.
As the cyclone moves through the Gulf of Mexico, NHC forecasters say it will undergo a process called rapid intensification. This means that warm water will act as fuel for the hurricane, increasing its wind speeds by at least 35 mph in just 24 hours.
As a result, a hurricane watch is in effect for Mississippi and almost all of Louisiana’s coast — from Cameron, Louisiana to the border of Mississippi and Alabama. The entire Alabama coast is under a tropical storm watch.
“There is a higher-than-normal confidence that a significant hurricane will impact a large portion of the northern Gulf coast by late this weekend and early next week,” the NHC forecast said on Friday morning. “Potentially devastating wind damage could occur where the core of Ida moves onshore.”
But flooding often does more damage than wind. Ida may bring “life-threatening” storm surge — a wall of water as high as 7 to 11 feet — along the coast from Morgan City, Louisiana, to Ocean Springs, Mississippi. Smaller surges are expected across the rest of Louisiana, Mississippi, and Alabama.
NOAA predicts up to a dozen more named storms this season
By definition, any cyclone-shaped storm with winds faster than 39 mph is a tropical storm. Storms get named once their winds reach that speed. After winds hit 74 mph, a storm becomes a Category 1 hurricane on the Saffir-Simpson scale.
Ida is the year’s ninth named storm; three other storms — Elsa, Grace, and Henri — also became hurricanes. Hurricane season runs from June 1 to November 30, with activity peaking around September 10.
The National Oceanic and Atmospheric Administration predicted that there will be a total of seven to 10 hurricanes in 2021, and up to 21 named storms. That includes three to five major hurricanes. A major hurricane is a Category 3, 4, or 5, with sustained wind speeds of at least 111 mph. Grace — which made landfall in Mexico as a Category 3 hurricane — has been the only major hurricane so far this year.
Overall, the average number of storms per season has increased, so NOAA recently updated the baseline numbers it uses to make seasonal hurricane predictions. The agency now defines an average season based on data from 1991 to 2010, when the average was 14 named storms, seven of which were hurricanes. Previously, NOAA considered an average season to have 12 storms in total, with six being hurricanes.
Climate change is making cyclones stronger, slower, and wetter
Earth’s warming increases the chance that a hurricane will be more devastating. Rising ocean temperatures in particular play a major role, since the temperature of the water below a storm influences its wind speed. A 1-degree-Fahrenheit rise in ocean temperature can increase a storm’s wind speed by up to 20 miles per hour.
That also enables storms to intensify in less time, So rapid intensification events have gotten more frequent over the last 40 years. One study found that the chance a hurricane will undergo rapid intensification went from 1 in 100 in the early 1980s to 1 in 20 by 2005.
Over the past 70 years or so, the speed at which hurricanes and tropical storms travel has also dropped about 10%. That’s a problem, since it means any given storm has more time to pummel an area with wind and rain. To make matters worse, a warmer atmosphere can hold more moisture, so a 10% slowdown in a storm’s pace could double the amount of rainfall and flooding that an area experiences. Peak rain rates of storms have increased by 30% over the past 60 years.
That increased rainfall, paired with rising sea levels, means cyclones will likely bring increasingly devastating flooding in the coming years and decades.