WRI 2024 Atlantic Tropical Outlook
David Bubbins, Meteorologist
2024 Atlantic Tropical Season Outlook
With summer on the horizon, this also means the Atlantic Hurricane Season is approaching. The Atlantic Tropical Season officially begins on June 01st and runs through the end of November, with a climatological peak during the month of September. When examining tropical activity over the past 30 years, the Atlantic basin experiences an average of 14 named storms, 7 hurricanes, and 3 major hurricanes. However, we are anticipating an above average season due to several factors, which includes a transition in the El Niño Southern Oscillation (ENSO) from an El Niño condition to a La Niña condition by the autumn.
Why is 2024 expected to be increasingly active?
Factor #1: Sea surface temperatures are currently running about 1-2°C above normal for much of the Tropical Atlantic and Caribbean basins. This trend is expected to persist through at least the early autumn months. In addition to increasing the atmospheric heat content, this warming will allow for a weaker subtropical high pressure to initially develop, with subsequent weaker trade winds over the tropical Atlantic.
Figure 1: Sea surface temperature anomalies across the North Atlantic as of April 25th. (Courtesy of PODAAC)
Factor #2: Decreasing trade winds and further warming of waters over the Atlantic attributed to the forecasted change in the ENSO cycle from the current moderate El Niño to neutral conditions by the summer, and then potentially La Niña conditions by the autumn.
The most recent year where a similarly strength moderate El Niño transitioned to a La Niña by the autumn was 2010. This year experienced a very active tropical season, with 21 named storms, 12 hurricanes, and 5 major hurricanes.
Factor #3: A more active than normal West African Monsoon, which is responsible for the transport of warm moist air from the Atlantic Equator. This local weather pattern plays a significant role in the development of westward moving tropical waves during the second half of the season.
When and Where can we expect Tropical Development?
Figure 2: Shows the most probable locations of tropical development in relation to the month. These trends are due to the transitioning La Niña.
Due to the expected active pattern this season, any clients or vessels with trade in the tropical Atlantic should pay close attention to tropical development. Ports and associated shipping lanes in the Gulf of Mexico, Bahamas, and US East Coast can be affected in the early parts of the season. As the season progresses, development is expected to shift towards the Caribbean and Windward Islands. Shipping interests in July through August should monitor the Caribbean and Windward Island shipping lanes. Late season development will shift towards the Cape Verde Islands tracking towards the Lesser Antilles and Winward Islands. Expect recurving of systems into the central Atlantic to effect North Atlantic shipping lanes.
WRI and their team of meteorologists will continue to work hard to keep you informed of any tropical threats affecting shipping lanes across the Atlantic and the rest of the world’s ocean basins. Dolphin Online’s Tropical Tracker and basin wide summaries typically provide a week’s notice for possible tropical storm formation. This will allow for any advanced notice of any potential tropical concerns and keep you and your crew, vessel, and clients safe from any tropical concerns.
