Ernesto — 2024

A tropical wave that left Africa on August 7 organized into a broad low and became a tropical depression about 390 nautical miles east of Guadeloupe at 1200 UTC August 12. It strengthened to Tropical Storm Ernesto that afternoon, moved across the Leeward Islands and north of Puerto Rico, became a hurricane on August 14, reached peak intensity on August 16, then recurved north-northeastward. Ernesto weakened before crossing Bermuda on August 17, later re-intensified briefly over the Gulf Stream on August 18–19, accelerated northeastward, began extratropical transition on August 20, and dissipated into a trough by 0000 UTC August 21. Ernesto made several landfalls as it developed and moved northwestward. It passed over Guadeloupe on August 13 as a 35–40 kt tropical storm, made landfalls on Montserrat (August 13) and St. John (U.S. Virgin Islands) the same day as a tropical storm, and moved about 40 n mi north of San Juan on August 14 as a 60‑kt tropical storm. The island landfall on Bermuda occurred at about 0830 UTC August 17 as a 75‑kt (Category 1) hurricane. The storm’s maximum intensity was 85 knots (about 98 mph) with a minimum central pressure of 967 mb, making Ernesto a Category 2 hurricane at its peak from 0000–1800 UTC August 16. A second brief peak of 85 kt occurred at 1200 UTC August 19 while the cyclone was well south of Newfoundland. Storm surge was modest in most areas. A tide gauge at the Bermuda Biological Station measured a storm surge of 2.27 ft above normal tide levels (peak water level 0.84 ft above Mean Higher High Water); Puerto Rico and the U.S. Virgin Islands generally reported inundations under about 0.5–0.8 ft. Rainfall was heavy in Puerto Rico, especially in the interior high terrain where totals of 5–15 inches were common; the highest measured total was 13.90 inches in Ciales County. The U.S. Virgin Islands saw 5–9 inches, with 8.96 inches near Charlotte Amalie, St. Thomas. Bermuda recorded about 6–8 inches of rain, including 6.98 inches at L.F. Wade International Airport, causing urban flooding. Ernesto was associated with three confirmed rip-current deaths along the U.S. Southeast coast (two in Hilton Head Island, South Carolina, and one in Surf City, North Carolina). Overall economic losses were estimated near $520 million (Aon), mainly from flooding and wind damage in Puerto Rico and the Leeward Islands; Puerto Rico experienced widespread power outages affecting about 1 million households and numerous river floods and mudslides that damaged roads, crops, and vehicles. The U.S. Virgin Islands had extensive outages (over 45,000 customers) and scattered structural damage; Bermuda had widespread power outages (over 25,000 customers) and mostly tree/utility damage but relatively minor structural losses. Noteworthy items include the storm’s large wind field and two separate intensity peaks (mid‑August and a brief re‑intensification over the Gulf Stream), and that Bermuda observed its lowest August surface pressure on record. NHC track forecasts for Ernesto were notably accurate (errors below recent 5‑year averages), while intensity forecasts tended to overestimate the peak strength and did not fully capture the brief weakening to tropical storm strength prior to Bermuda landfall.