Based on reports of sustained hurricane-force winds from Barbados, Tropical Storm Elsa was upgraded to a hurricane on Friday morning, the first of the 2021 Atlantic hurricane season. Elsa became the earliest hurricane to form in the Atlantic Main Development Region (MDR) of the satellite era, and is the first July hurricane in the eastern Caribbean Sea since Hurricane Emily in 2005. A hurricane in this region is very concerning for so early in the season, and could be a warning sign of a very active hurricane season this year. What makes Elsa’s intensification so unexpected is its rapid forward speed – near 30 mph – though the forward speed may have played a role in Elsa attaining hurricane-force winds.

As of 5:00 p.m. EDT Friday, Hurricane Elsa was centered near 14.2°N 63.7°W, and was moving westward at a brisk 30 mph. Maximum sustained winds were 75 knots (85 mph), with an estimated minimum pressure of 991 mb. Elsa rapidly intensified last night and this morning, with an eye-like feature being visible in radar imagery. Elsa’s quick intensification was poorly forecast by the global models, and it appears global models are having issues resolving the cyclone. Hopefully, reconnaissance aircraft data can help model forecasts improve in the coming cycles. Although Elsa has become a hurricane, its forward speed is limiting its ability to become more symmetrical, with the strongest winds mostly north and east of the center and very light winds south and west of the center. Since Elsa has become a hurricane, it appears much less likely now that it will degenerate into a tropical wave in the central Caribbean Sea, as has been suggested by most ECMWF model runs. Elsa has about 36 hours left to strengthen until it approaches the Greater Antilles, which could disrupt Elsa’s circulation and stall intensification or even weaken the cyclone. The exact track that Elsa takes will determine how much time it has over water, as the ECMWF model continues to insist that Elsa’s circulation will dissipate over western Hispaniola. This scenario does not seem likely because the ECMWF has been consistently way too weak with Elsa, and likely has not resolved the cyclone correctly. In contrast, the HWRF model, which has consistently been the strongest model with Elsa, keeps Elsa farther south and over water for longer, strengthening Elsa to a powerful major hurricane. Elsa’s intensity forecast remains tricky due to the hurricane’s fast movement, but Elsa’s forward speed is likely to decrease to less than 15 knots (20 mph) in about 36 hours or so as it nears the Greater Antilles. The potential for hurricane impacts has resulted in a Hurricane Warning being issued for much of southern Hispaniola. Elsa’s most likely chance to intensify further will be around this time if it is able to stay over water. If Elsa’s circulation is able to survive the rugged terrain of Jamaica and eastern Cuba, the cyclone will likely enter the Florida Straits and could make landfall in the Florida Peninsula. However, in the Florida Straits and southeastern Gulf of Mexico, wind shear is expected to increase slightly, and it appears unlikely Elsa will still be a hurricane by that time. Regardless, residents of Florida should closely monitor the progress of Elsa.