Tracking The Tropics with Meteorologist Tony Nargi
Hurricane Erin has weakened overnight thanks to an Eyewall Replacement Cycle (ERC), which is common among intense Hurricanes. She has dropped from a category 5 hurricane down to a category 3, with maximum sustained winds of 125 mph. She will likely intensify back to a category 4 later today into tomorrow morning as she continues to move over very favorable conditions.
What is an Eyewall Replacement Cycle? It's exactly what it sounds like! When a hurricane eye gets too small, such as Hurricane Erin's from yesterday at around 4:40 pm (below), the strong thunderstorms that make up the eyewall of the hurricane are not able to stay organized and sustain themselves. In layman's terms, the eye collapses in on itself, and strong thunderstorms setup outside of the old eyewall. This leads to the development of a new eyewall outside the old one, and this process can take anywhere from 12 hours to 3 days. As this process occurs, the hurricane will typically weaken in strength, which is why hurricanes don't typically stay at category 5 for long periods. Once Hurricane Erin finishes her ERC, expect her to intensify once again.
Her current forecast has not changed much and is still expected to "split the uprights" between the Cape Hatteras and Bermuda, keeping her away from any major land masses. Cape Hatteras will see the highest chance of being impacted by some outer bands of Erin on Thursday, but most of our area will steer clear of any direct impacts from Erin. Winds could gust over 40 mph on the Outer Banks Thursday, however sustained tropical storm force winds are unlikely, and hurricane force gusts are very unlikely.
Some showers and thunderstorms may be possible on Thursday from the far outer bands of Erin, however most of the rainfall will stay out with the fishes. The main impact from Hurricane Erin will be strong rip currents and beach erosion, especially for the Outer Banks. Wave heights could be between 10-15' feet out over the Outer Banks on Thursday!
Even though Erin will deliver some coastal impacts to our region, she is still on an ideal track to keep the worst of her effects away from land. There is now another area in the Central Atlantic that we will have to monitor once Erin is far away from our region. A new tropical wave moving off of West Africa has a 20% chance of forming into a tropical depression over the next 7 days. We'll keep you updated on this new wave along with Hurricane Erin throughout this week!
