Bryan Norcross: Erin explodes into Cat 4 – still likely to avoid landfall but cause significant impacts

Hurricane Erin rapidly intensified overnight arsenic it developed a small, symmetric core. The oculus shrunk successful size to astir 9 miles, which has the equivalent effect to a fig skater drafting successful their arms to rotation faster. The National Hurricane Center had predicted accelerated intensification with Erin, but it's happened up of schedule.

The tempest has shed the particulate and adust aerial that was limiting the intensification process and is moving implicit adjacent warmer ocean water. The forecast calls for it to intensify a spot much – a Category 5 can't beryllium ruled retired – earlier the apical winds travel down and the tempest grows successful size arsenic it turns northbound connected a way offshore of the U.S. East Coast.

Erin's diameter is forecast to summation four- oregon five-fold implicit the adjacent 5 oregon six days. Large hurricanes enactment overmuch much vigor into the ocean, truthful important water impacts are expected on each coastal sections from the Bahamas to Canada, including, of course, the U.S. East Coast.

Hurricane Erin outer image

(Bryan Norcross / NOAA)

Today, Erin volition walk good to the northbound of Anguilla, St. Martin, and the adjacent islands, with the halfway passing immoderate 200 miles northbound of Puerto Rico and the Virgin Islands tomorrow. Tropical storm-force winds implicit 40 mph are lone expected to widen astir 140 miles southbound of the storm's center. Still, bands of rainfall volition interaction the islands.

Gusty squalls from feeder bands rotating into the hurricane volition walk done the islands contiguous and tomorrow. Winds could gust 40 to 50 mph, and aggravated downpours could origin flash flooding successful mountainous terrain. The National Weather Service is forecasting 2 to 4 inches of rainfall with immoderate areas receiving 6 inches oregon more. The gusts could origin immoderate powerfulness outages.

On Puerto Rico and successful the Virgin Islands, enactment alert of alerts issued by the National Weather Service successful San Juan.

After Erin passes Puerto Rico tomorrow, it volition arc northbound offshore of the Bahamas Monday and Tuesday. The upwind signifier is forecast to beryllium highly supportive of an aggravated hurricane astatine that clip - the water h2o is unusually lukewarm eastbound of the Bahamian Islands and the atmospheric signifier is forecast to beryllium precise supportive. As a result, Erin is forecast to beryllium an highly beardown hurricane done this period, but with fluctuations successful strength owed to interior processes wrong the storm.

By precocious Tuesday, Erin volition person passed the Bahamas and volition beryllium heading northbound betwixt the U.S. East Coast and Bermuda. Everyone is ace fortunate that this tempest is threading the comparative needle. But important impacts volition inactive beryllium felt on the seashore from Florida to New England.

Hurricane Erin's forecast cone and statistics

(Bryan Norcross / NOAA)

Expanding Hurricane Erin volition make immense waves successful the unfastened water and impart vigor to the h2o that volition radiate toward the seashore successful the signifier of strong, long-period swells. This vigor volition make almighty waves susceptible of eroding beaches and highly beardown and aggravated water currents.

The unsafe conditions volition commencement successful Florida and connected the Southeast seashore connected Tuesday, spreading to the Northeast and New England by Thursday. Beaches whitethorn beryllium closed and boaters beware. Follow section instructions.

Cape Hatteras, North Carolina is highly vulnerable, of course. The National Hurricane Center volition beryllium analyzing the impacts to communities determination and each on the seashore and supply plentifulness of informing if enactment is required.

Bermuda volition beryllium connected the beardown broadside of the hurricane. Most likely, the worst of the tempest volition not interaction the island, but important effects can't beryllium ruled retired yet.

It is highly fortuitous that the tempest looks to walk done the spread betwixt the Carolinas and Bermuda, though don't minimize the information astatine the beaches and successful waterways unfastened to the Atlantic arsenic the tempest goes by.

Off the Carolinas

The National Hurricane Center is coating a low-probability citrus offshore of Cape Hatteras, North Carolina. Once again, an aged acold beforehand is producing immoderate thunderstorms implicit the Gulf Stream and there's a flimsy accidental that a strategy could signifier that has capable tropical characteristics to beryllium designated a depression. There is an extracurricular accidental it could concisely get beardown capable to beryllium named.

There is nary menace to land, and the strategy volition beryllium heading retired to oversea implicit the adjacent fewer days.

Atlantic tropical overview Aug. 16, 2025. 

(Bryan Norcross / NOAA)

Next Thing to Watch

A disturbance that has conscionable moved disconnected Africa is forecast to way crossed the tropical Atlantic this week. There's reasonably bully statement successful the assorted machine forecasts that it volition get astatine the Caribbean islands astatine the extremity of the week. But determination is nary statement connected what volition hap next.

Some machine forecast models make it into a important storm, which could beryllium a menace to land. Others bash fundamentally thing with it. As always, forecasts are mediocre for systems that person not yet developed, truthful there's thing to look astatine yet.