Erin Stuns as a Weekend Category 5, to Bring Life-Threatening Surf to the Eastern U.S. Seaboard this Week

Monitoring another disturbance bound for the islands from Friday into the weekend

Category 5 Hurricane Erin around sunset Saturday, August 16, 2025. Credit: NOAA/CIRA

Hurricane Erin dazzled forecasters over the weekend, putting on a spectacular show of strength rarely observed, becoming only the 43^rd Atlantic-basin Category 5 hurricane on record and tying Camille in 1969 for the 4^th earliest-forming Category 5 ever recorded.

Erin strengthened 85 mph in only 24 hours from a borderline hurricane to a 160-mph Category 5, a dizzying intensification rate only exceeded by three other Atlantic basin hurricanes – Wilma (2005), Felix (2007), and Milton (2024).

Measuring Erin’s intensity change by pressure fall is even more impressive, and its 78 mb drop from 993 mb Friday afternoon to 915 mph by the same time Saturday is only eclipsed by two other hurricanes – Wilma (97 mb in 24 hours) and Milton (79 mb in 24 hours) – both October hurricanes.

Maximum wind (black line) and minimum pressure (blue line) history for Erin through Monday morning (August 18^th, 2025). Note the precipitous fall in pressure from Friday (August 15^th, 2025) to Saturday (August 16^th, 2025) afternoon. Credit: Cyclonicwx.com

Thankfully, Erin’s rapid strengthening happened largely over water as its center passed about 100 miles north of the northern Leeward Islands and some 180 miles northeast of the U.S. Virgin Islands and Puerto Rico on Saturday.

Erin was a remarkably small hurricane, a common feature of our strongest hurricanes, with maximum winds extending out from the center only about 3 miles (for the average hurricane, the radius of maximum winds is closer to 20 miles).

With hurricane conditions extending only about 25 miles south of Erin’s center, no sustained hurricane winds were observed through the islands as Erin passed to their north and east over the weekend.

As we previewed in Friday’s newsletter, gusty squalls in Erin’s trailing rainbands did bring tropical storm winds to Puerto Rico and the U.S. Virgin Islands, however. Gusts to 53 mph were observed in Culebra in Puerto Rico and 49 mph in Charlotte Amalie on Saint Thomas in the U.S. Virgin Islands, according to the National Weather Service. Erin’s gusty winds knocked out power to over 150,000 customers in Puerto Rico (~10% of the island) over the weekend, according to LUMA Energy, but most customers had power restored as of Monday morning.

Tortola in the British Virgin Islands reported almost 10 inches of rain on Saturday from Erin and widespread flooding was reported throughout the islands, where flood watches remain in effect today. Conditions in the islands should dry out by tomorrow as Erin continues to pull away.

Rare pictures from inside Erin’s eye

Both Air Force and NOAA hurricane hunters flew Erin nearly round-the-clock over the weekend, sending back spectacular pictures and data critical to hurricane forecasters.

Among data collected was radar from inside the eye that showed with stunning detail intense mesovortices rotating around Erin’s inner eyewall Saturday morning.

Radar image from inside the eye of Hurricane Erin Saturday morning (8:06 AM ET August 16^th, 2025) captured by hurricane hunters as it strengthened into a Category 5 hurricane. The filaments or fingers curling inside the eye of Erin are known as mesovortices, a feature rarely observed on radar since we only see them in the strongest of hurricanes. They play an important role in extreme intensification, helping to hasten strengthening, but are also associated with extreme and exceptionally dangerous, tornado-like winds at the surface. Credit: Carson Thomas (@ItzRoch11)

These fingers curling inside the inner eyewall are rarely observed on radar since they only occur in our strongest hurricanes. They not only play a crucial role in extreme episodes of intensification, but are also associated with extreme, tornado-like winds at the surface and are exceptionally dangerous to encounter. It’s one of the main reasons you should never venture outside in the eye of a hurricane if sheltering-in-place.

Because Erin’s eye was so small, hurricane hunters also captured dramatic photos and videos rarely seen from inside a hurricane. The photo below was taken Saturday as NOAA hurricane hunters passed into Erin’s eye at only about 8,000 feet above the ocean surface.

Photo taken by NOAA Hurricane Hunters Saturday showing the violent sea state from the extreme winds of Erin’s eyewall (bottom right) but the much less agitated seas in the upper-left from the relative calm of Erin’s eye. Credit NHC/NOAA

It shows the extreme gradient of strong winds in Erin at the time, with violent, wind-whipped blue seas in Erin’s eyewall on the right, but much less agitated seas from Erin’s relatively calm eye in the upper-left part of the photo.

NOAA Hurricane Hunters also shared this breathtaking video from their last pass through then Category 5 Erin’s eye.

NOAA Hurricane Hunters as they passed through the eye of Category 5 Erin around 10 AM ET Saturday morning (August 16^th, 2025). Credit: NOAA/Lt. Cmdr. Josh Rannenberg

Simultaneously the Air Force Reserve Hurricane Hunters passed through Erin’s eye, capturing this video looking up inside Erin’s eye Saturday morning (August 16^th, 2025).

Video looking up inside the eye of Category 5 Hurricane Erin from Air Force Hurricane Hunters Saturday morning (August 16^th, 2025). Credit: U.S. Air Force 403^rd Wing

These data and pictures are more than just eye candy for forecasters, helping them quickly correct their initial underprediction in Erin’s intensity early Saturday.

Intensity forecasts from the National Hurricane Center for Erin from their early forecasts beginning August 11^th. The black line is the actual intensity of Erin and the thinner colored lines show NHC official forecasts. After being too quick on the trigger early on, something we discussed in Friday’s newsletter, forecasts significantly undershot Erin’s rapid intensification when it finally happened. Data from the hurricane hunter airplanes and microwave satellites helped forecasters quickly correct the forecast. Credit: Brian McNoldy/University of Miami

Much larger and powerful Erin to bring dangerous waves and beach erosion

Since its rapid intensification early Saturday, Erin went through a metamorphosis, temporarily weakening, but shedding its smaller eye for a newer, much larger one.

Even though its winds are below its peak Saturday, Category 4 Erin is now a larger and more powerful hurricane. While the center is expected to remain well offshore, the hurricane is expected to bring a period of dangerous seas, significant beach erosion, and life-threatening rip currents up and down the U.S. Eastern Seaboard this week.

Coastal flood watches and hazardous surf advisories have already been hoisted from the southeast U.S. to the Mid-Atlantic and Northeast. As Erin makes its closest approach to North Carolina’s Outer Banks on Wednesday and early Thursday, it could bring seas topping 20 feet or higher just offshore, creating treacherous marine conditions and major coastal problems, including severe flooding and beach erosion, especially oceanside along Highway 12.

Significant wave heights (average of the highest 33% of waves) from the American GFS model through Saturday morning. Individual waves could top 100 feet in the western Atlantic this week with Erin.

Though southeast Florida will see elevated seas and swell from Erin, it will be mostly shielded by the Bahamas, so coastal waters south of Palm Beach County will experience fewer problems from Erin’s passage today and Tuesday.

Erin’s biggest impact on the U.S. will be along the immediate coast from long-period waves and wind-whipped seas, and, as we discussed in newsletters last week, its violent core and strongest winds will stay well offshore between Bermuda and the U.S.

Bermuda may see gusty winds away from Erin as the hurricane passes 300 to 500 miles to their west, but significant direct, non-marine impacts appear unlikely.

Monitoring the next wave for the weekend

Another tropical wave currently in the eastern Atlantic is poised to develop as it moves generally westward toward the northeastern Caribbean for late week into the weekend.

Models are slow on development the next few days but conditions should gradually become more conducive as it moves farther west. The Lesser and Greater Antilles, including Puerto Rico and the U.S. Virgin Islands, should follow the progress of this disturbance this week.

Forecast low-pressure tracks from the European model ensemble system (top) and American GFS ensemble system (bottom) through early Saturday showing a general track toward the northeastern Caribbean islands. Credit: Weathernerds.org

Until the system fully forms, we won’t have a good handle on its future beyond this week, but it’s something we’ll need to monitor for early next week. There are a lot of what-ifs ahead, including island impediments, so be patient and be extra skeptical of longer-range models until we have a defined system.

We’ll of course keep you updated as we have more clarity on the forecast in the days ahead.