Bonnie (2010)

A small tropical cyclone formed from a tropical wave in the central Bahamas on 22 July 2010 and lasted only a few days. A weak low became a tropical depression at 0600 UTC 22 July just south of Acklins Island, and it intensified into Tropical Storm Bonnie near 0000 UTC 23 July southwest of Georgetown on Great Exuma. Bonnie moved northwestward across the central Bahamas, reached peak strength on 23 July while crossing southern Andros Island, then weakened as it approached southern Florida. Convection waned under strong wind shear and dry air; Bonnie degenerated to a remnant low by 0000 UTC 25 July about 60 n mi southeast of the Mississippi River and the low made a final landfall near southeastern Louisiana before dissipating over east‑central Louisiana later that day.

Bonnie made multiple landfalls in the Bahamas and southern Florida. The best-track identifies landfalls on Ragged Island and Andros Island, Bahamas, on 22–23 July (Andros landfall about 0515 UTC 23 July). In the United States Bonnie made landfall near Elliot Key, Florida at about 1430 UTC 23 July with maximum winds around 35 kt (40 mph by conversion shown below), then the remnant low moved ashore near the southeastern tip of Louisiana about 0004 UTC 25 July.

The storm’s maximum intensity was 40 kt (46 mph) with a minimum central pressure of 1005 mb, reached at 0600 UTC 23 July. That peak corresponds to a weak tropical storm (well below hurricane strength). Aircraft and station data supported the 40 kt peak, including a 10‑minute average wind report of 37 kt from Mangrove Cay and flight-level reports used in the best track.

Storm surge and rainfall were modest. Reported storm surge and storm-tide observations include a storm tide of about 1.28 ft and a storm surge of 0.92 ft at Virginia Key, Florida; tide and surge reports were generally small elsewhere in South Florida. Rainfall totals were light for a tropical cyclone in the area, with a maximum measured storm total of 3.25 inches at Bal Harbour, Florida and other South Florida totals typically around 2 inches (examples: Metro Zoo 2SSW 2.59 in over 48 h, Country Walk 2.39 in, Perrine 2.10 in).

Impacts and casualties were minimal. No fatalities were reported. Damage was minor and mostly limited to coastal southeastern Florida: small, shallow‑rooted trees were blown down in Miami‑Dade County, and about 15,870 customers lost power across Miami‑Dade and Broward Counties. No damage reports were received from the Bahamas.

Noteworthy items: Bonnie was a small system that reached only minimal tropical‑storm strength and its genesis was not well forecast in advance; NHC forecasts for the track performed about as well as the recent average, while intensity forecasts were slightly worse than the recent average. The cyclone weakened quickly under increasing upper‑level winds (shear) and dry air, which prevented re‑strengthening over the Gulf of Mexico.