Andrea (2007)

Andrea developed off the southeastern United States coast in early May 2007. The system began as a strong extratropical cyclone near the mid‑Atlantic coast on 6 May, producing very strong winds and large waves, then moved westward and gradually lost its frontal structure. By 0600 UTC 9 May, while centered about 150 nautical miles east of Jacksonville, Florida, the circulation had become warm‑core and symmetric enough to be classified as a subtropical cyclone. Andrea weakened steadily after that and became a remnant low by 0000 UTC 11 May; the remnants moved near the central Florida coast before being absorbed by a front by 14 May.

Andrea did not make a direct landfall as a subtropical cyclone. Most of the hazardous impacts along the coast from North Carolina southward through Florida occurred during the earlier extratropical phase on 6–8 May, when hurricane‑force winds and very large waves affected the coast. A Tropical Storm Watch was issued from Altamaha Sound, Georgia, to Flagler Beach, Florida on 9 May and discontinued on 10 May.

The storm’s maximum analyzed intensity as a subtropical cyclone was 50 kt (about 58 mph) at 0600 UTC 9 May, with a minimum central pressure near 1001 mb. During its earlier extratropical stage, a nearby buoy (41001) reported sustained winds to 55 kt with a gust to 70 kt, a value the report cites when discussing stronger winds in the pre‑Andrea phase.

Storm surge and rainfall were modest along the coast relative to typical hurricanes but locally significant because of large waves and high tides. Reported storm surge values included about 2.64 ft at Fernandina Beach and 2.83 ft at St. Simons Island; corresponding storm tides reached about 7.88 ft and 8.09 ft at those locations. Rainfall totals were generally light, typically under 1 inch across the southeastern United States; specific station reports include 0.37 in at Fernandina Beach, 0.36 in at Mayport, and 0.77 in at Jacksonville Beach.

There were no deaths directly attributed to Andrea as a subtropical storm, but the pre‑Andrea extratropical cyclone was directly responsible for six deaths: four crew members from the sailboat Flying Colours off North Carolina (7 May), a kayaker near Seabrook Island, South Carolina (8 May), and a surfer near New Smyrna Beach, Florida (9 May). Coastal damage was mainly from large waves, higher‑than‑normal tides, coastal flooding, and beach erosion; 21 shipping containers were lost overboard from the vessel Paris Express on 6 May, and debris washed ashore from Cape Lookout, North Carolina, northward to the Virginia border.

Notable aspects include Andrea’s early‑season timing—it was the first May cyclone in the Atlantic basin since 1981 and one of the earliest on record—and the transition from a strong extratropical cyclone to a subtropical cyclone just east of Florida. Forecast track and intensity errors for Andrea were below the long‑term average for the National Hurricane Center, and pre‑storm special statements described the hazards from the pre‑Andrea extratropical cyclone beginning on 8 May.