Earl has weakened very slightly, and just happened to cross the Cat 3-4 threshold to 110kts (943mb central pressure). It's currently located about 725 miles SSE of Cape Hatteras, NC and heading NW at 14kts. Hurricane Warnings now cover all of the NC coast and Hurricane Watches cover the southern parts of the VA coast and the DelMarVa peninsula. The closest approach to the coast is expected early Friday morning, still as a major hurricane. Even if a direct landfall doesn't occur (meaning the center of the eye crosses the coastline), the western half of the storm, and perhaps even the eyewall, will affect land with flash flooding, strong damaging winds, and major beach erosion. Coastal areas from central NC up to Cape Cod can expect some storm surge, generally in the 2-5' range.
Tropical Storm Fiona has been improving in satellite appearance, but not drastically. It's approaching the northern Leeward Islands, but will steer away toward the NW before affecting them as much as Earl did 2-3 days ago. Its environment is much less favorable than Earl's was at the same location, and the official forecast actually weakens the storm to a Depression in 5 days as it recurves and heads n toward Bermuda. At 15Z, the intensity is 50kts and 998mb.
Elsewhere, an easterly wave that exited the African coast on the 28th has gradually been getting better organized, and has been upgraded to TD9. The majority of models develop this system into TS/Hurricane Gaston. It's about 1800 miles east of the Windward Islands, moving W at 13kts, and the intensity is estimated at 30kts/1006mb. It will track to the WNW over the next several days... still a week away from the Lesser Antilles.
I'd like to introduce a couple 'guest writers' who volunteered to send these updates out while I'm on vacation for the next week. Kate Musgrave and Gus Alaka, both very knowledgeable colleagues here at CSU, will keep you up-to-date with the activity across the basin. Thanks in advance to Kate and Gus!
Please visit my tropical Atlantic headquarters.