Hurricane Erin Explosively Strengthening – Close to Category 5

Hurricane Erin is currently at Category 4 hurricane with sustained wind speeds of 145 mph and gusting to even higher levels. NOAA Hurricane Hunters flying into the storm also found that the minimum pressure was down to 935 mb as of 8:00 am AST on August 16. Erin is literally strengthening as I write this. In the 5:00 am AST update from the National Hurricane Center, sustained winds were 130 mph. These numbers place Hurricane Erin at Category 4 on the Saffir-Simpson Wind Scale. and very close to a Category 5 storm. It also represents yet another recent example of explosive rapid intensification.

Candidly, when I looked at the satellite presentation of Erin this morning, I said, “Wow.” It had that eerily perfect structure meteorologists like me dread. Such attributes include a well-defined eye, an intact eyewall, and a healthy outflow region in the upper part of the atmosphere. It also has something else that concerns me. There is plenty of very warm water in the path of the storm. In fact, some of the warmest sea surface temperatures are still in front of the storm.

Will Erin make a run for Category 5, which means sustained winds greater than 157 mph? Here’s what the National Hurricane Center is saying about Hurricane Erin in its 8:00 am AST update on August 16. They wrote, ” Erin is expected to continue to rapidly strengthen over the next 12 hours while it remains in favorable conditions of warm water, low wind shear, and in an environment of high moisture…. Strengthening could
continue through tonight.” With that statement, I am certainly not ruling out Category 5, but it really doesn’t matter. Category 4 is strong enough. Thankfully, wind shear will increase early next week.

Rapid intensification is defined as a storm gaining 35 mph of wind speed in less than 24 hours. At 5 pm on Friday, Erin was a Category 1 hurricane with 75 mph winds. It increased by 70 mph in 15 hours according to Washington Post and MyRadar Weather Radar meteorologist Matthew Cappucci. Rapid intensification is a big deal, but I continually see storms going well beyond the rate for RI. My hunch, as an expert in this field, is that our current metrics of “weather extremes” like RI and “100-year flood” are becoming obsolete. Thankfully, Erin will not make a direct hit on the U.S., but several RI hurricanes have in recent years. They include Hurricane Ida (2021), Hurricane Ian (2022), Hurricane Beryl (2024), Hurricane Milton (2024), Hurricane Helene (2024), and several others. I wrote last year about how RI near the coast creates a new reality for hurricane planning and response.

Erin is expected to pass between Bermuda and the East Coast. NHC went on to say, “Although Erin is a somewhat compact hurricane now, the models are in strong agreement that the system will grow in size over the next several days.” By Wednesday it could be two or three times its current size. That means the U.S. East Coast could certainly experience large swells and an elevated rip current threat.

As I close, it is worth mentioning that a small disturbance is currently producing showers and thunderstorms off the North Carolina coast. It is not Hurricane Erin and only has a 10% chance of further development in the coming days. However, it certainly will be a nuisance for people along the Carolina and Virginia coasts this weekend.