Dorian is moving toward the SC and NC coasts this morning being tracked by coastal radars and USAF missions.
The very large eye of Dorian (50 miles in diameter) is currently located 70 miles SSE of Charleston, SC and is moving toward the NNE at 8mph.
Maximum sustained winds are 115mph making Dorian a category 3 hurricane. Dorian has become a very large storm with tropical-storm-force winds extending outward 195 miles from the center.
The overall cloud pattern of the hurricane remains fairly well developed, but with more and more of the circulation interacting with the US SE coast, Dorian is starting to show some signs of degradation on its NW side. NOAA buoy 41004, 50 miles SE of Charleston is currently gusting to 85mph with 23-foot seas.
Dorian is moving through a break in the subtropical ridge over the eastern US and a turn toward the NE is expected over the next 24 hours and then acceleration as Dorian is captured by a trough over New England. On this track, Dorian will likely move very close it not make landfall on the NC coast tonight into Friday and then move rapidly toward the Canadian maritime areas.
Given the latest track guidance and the expansion of the tropical-storm-force winds field ... this requires the issuance of a tropical storm watch of portions of southern New England.
Dorian has gained a little intensity overnight as the hurricane has been moving along the Gulf Stream and is within a fairly light wind shear environment. Dorian’s biggest battle is with its massive size that is not allowing a tight inner core to re-develop and instead spreading the energy out over a very large area.
While the winds are around 115mph, the size of the wind field makes Dorian a very dangerous hurricane as any one location would experience hours and hours of adverse conditions and these large systems result in significant storm surge flooding (think Ike).
Charleston recently reported a wind gust to 68mph. Wind shear will likely begin to increase from the SW over the next 24 hours and slow but gradual weakening of the hurricane is likely as it moves across eastern NC and then across the western Atlantic.
Significant storm surge flooding is likely along the SC and NC coast today. In fact, the current water level forecast for Charleston Harbor, if verified, would place Dorian as the second-highest tidal reading between Hugo and Irma.
Large portions of the SC low country will experience storm surge flooding today into Friday as well as portions of the NC coast. TS to near hurricane-force winds will batter the coastal areas for many hours as the large wind field of Dorian progresses NE at around 10mph.