Andrea (2013)

A broad area of low pressure in the southern Gulf of Mexico consolidated into Tropical Storm Andrea on 5 June 2013 about 270 nautical miles southwest of St. Petersburg, Florida. Andrea moved slowly northward at first, then turned northeast and accelerated on 6 June as it was steered between an upper-level trough and a subtropical ridge. After crossing Florida it raced northeastward along the southeastern U.S. coast, became extratropical over northeastern South Carolina on 7 June, and its post‑tropical center moved offshore near New Jersey and across Long Island into the Gulf of Maine before being absorbed on 9 June.

Andrea made its only U.S. landfall late on 6 June about 10 nautical miles south of Steinhatchee on the northwestern Florida peninsula. After landfall the center crossed northeastern Florida and southeastern Georgia; the center passed over Savannah, Georgia near 0700 UTC 7 June while the system was still producing tropical-storm-force winds. The cyclone transitioned to an extratropical/gale‑force low over northeastern South Carolina later on 7 June.

The maximum sustained winds in Andrea were estimated at 55 kt (about 63 mph) with a minimum central pressure near 992 mb. That peak intensity (55 kt) occurred on 6 June, so Andrea was a moderate tropical storm at its strongest (below hurricane strength).

Storm surge along the West Coast of Florida was mostly 1–3 feet, with a maximum surge of 4.55 ft recorded at Cedar Key. Other notable surge readings included McKay Bay Entrance (3.34 ft), Old Port Tampa (2.84 ft), Clearwater Beach (2.64 ft), and St. Petersburg (2.63 ft). Rainfall totals were generally 3–5 inches along the U.S. East Coast to New England, with isolated higher amounts. Southeast Broward and northeast Miami‑Dade Counties received very heavy localized totals on 7–8 June; North Miami Beach reported 15.28 inches storm total and 13.94 inches in 24 hours, producing severe urban flooding in the Miami–Fort Lauderdale area. Many inland sites from Florida through North Carolina reported 5–7 inches, with some higher localized totals farther north.

Andrea was associated with 11 confirmed tornadoes in the United States (10 in Florida, 1 in North Carolina) and produced generally minor property damage in the U.S.; insured losses were below the $25 million catastrophe threshold used by Property Claims Service. The NHC attributed one direct death (a missing surfer in Horry County, South Carolina) and three indirect deaths from traffic accidents (one in Virginia and two in New Jersey). Cuba experienced heavy rains and freshwater flooding from the precursor low, with locally over 12 inches reported in Pinar del Río province and some reported tornadoes and property damage there.

Noteworthy points: Andrea formed from a complex blend of the remnant of Hurricane Barbara and other disturbances, and its genesis was reasonably well forecast in advance though the timing of genesis was shifted later than initial expectations. NHC track forecasts verified well at 24–36 hours, and intensity forecasts had a slight low bias because Andrea strengthened more than expected in a moderate-shear environment.