By
Alex Sundby
Senior Editor
Alex Sundby is a senior editor at CBSNews.com. In addition to editing content, Alex also covers breaking news, writing about crime and severe weather as well as everything from multistate lottery jackpots to the July Fourth hot dog eating contest.
Read Full Bio
Updated on: August 16, 2025 / 11:25 PM EDT
/ CBS News
11:30 a.m. tropical update: Hurricane Erin has intensified into a cat 5 storm with winds of 160 mph
11:30 a.m. tropical update: Hurricane Erin has intensified into a Category 5 storm, winds of 160 mph
02:09
Erin rapidly strengthened into a Category 5 hurricane over the Atlantic Ocean Saturday before weakening slightly to a Category 4 status, but it remained a “formidable” storm while it underwent a process known as an “eyewall replacement cycle,” the National Hurricane Center said.
“Some fluctuations in intensity are expected over the next couple of days due to inner-core structural changes,” the Miami-based hurricane center said.
A Category 4 hurricane is defined as having maximum sustained winds of 130 mph or higher.
The center of Erin was skirting to the north of the northern Leeward Islands, which includes the Virgin Islands. It was forecast to move away from the Virgin Islands and Puerto Rico on Sunday, and then pass to the east of Turks and Caicos Islands and the southeastern Bahamas Sunday night and Monday. The hurricane center warned that heavy rain in some areas could trigger flash flooding, landslides and mudslides.
A satellite image of Hurricane Erin as it churns in the Atlantic at 8:20 p.m. Eastern Time on Aug. 16, 2025.
NOAA
Tropical storm watches were in place for Turks and Caicos Islands.
Erin, which grew from a tropical storm into a hurricane on Friday, is the first hurricane of the 2025 Atlantic season.
Forecasters urged people in the Caribbean islands to monitor Erin’s progress, warning of the potential for heavy rainfall and life-threatening surf and rip current conditions.
Erin is not currently forecast to impact the United States, but meteorologists continue to watch it closely.
What is an eyewall replacement cycle?
The hurricane center disclosed Saturday night that Erin was undergoing an “eyewall replacement cycle,” which, according to CBS News meteorologist Nikki Nolan, is when the storm has become so significantly powerful that its eyewall, its strongest part, reaches maximum strength.
When this happens, Nolan said, the eyewall itself becomes so intense from intaking the available energy from its environment that a new eyewall will begin to build on the outside of the existing, inner eyewall. Once the new eyewall is created, it cuts off the fuel to the original eyewall.
Furthermore, as the new eyewall gains strength to keep up with the power of the storm, the radius of the eye itself will become much larger than it originally was,