As of 8 PM (Tuesday, 08/23), Hurricane Hunter aircraft have found a significant drop in the central pressure of Hurricane Irene, now located 25-40 knots south of the Turks and Caicos Islands (the easternmost extent of the Bahamas) and wobbling WNW (305 degrees) at 10 knots.
Irene has been fighting off some southwesterly shear and the intrusion of dry air from the high terrain of the Dominican Republic, but as the storm begins to pull away from Hispaniola, and the subtropical trough of low pressure sitting in the western Caribbean backs off, the storm is finally freed to intensify. Signs of this uptick in strength began about three hours ago as the outflow in the western quads of the storm began expanding and convection re-intensified over the center. Now a series of well-defined concentric rings of cold clod tops are taking shape within the central dense overcast and the minimum central pressure has fallen from 981 mb to 969 mb in the last 9 hours (by definition, this is a rapid intensification if it continues at this rate).
I expect that by the time you wake up tomorrow morning, Irene will be “eying” the Southeast directly…and will probably be a category 3 hurricane (or darned close). The storm has the potential to eventually become a category 4, but I doubt it will have that intensity by the time it nears the Carolinas.
As for the end-game…the forecast models seem to be coming into better agreement as to the likely landfall location – somewhere between Wilmington, NC and Cape Hatteras (highest probability: Morehead City) some time late Saturday night. There is even improving agreement about the trajectory of the storm after it makes landfall, with an increasing number of the major global models seeing a path that would take Irene back over open waters near the VA/NC border and then perhaps 10 or 20 degrees east of north from there to somewhere on Long Island or Block Island…though this last part of the forecast continues to have a decent amount of spread.
Further updates will follow as more information becomes available. Folks living in North Carolina know the drill…it’s time to prepare, and if you’re in an evacuation prone area, you might save yourself some aggravation and leave a little early…and you should DEFINITELY make sleeping arrangements for the weekend.