The 2024 Atlantic hurricane season will officially begin on June 1, just slightly over two months away. As the start of the season draws closer, confidence increases in forecasting the upcoming hurricane season. The 2023 Atlantic hurricane season finished with above-average activity despite a strong El Nino, with 20 named storms, 7 hurricanes and 3 major hurricanes. However, it was the least destructive season since 2014, and no names were retired for the first time since that year. It appears as if they key factors are all lining up for a potentially extremely active Atlantic hurricane season, with near-record warm sea surface temperatures in the tropical Atlantic, a La Nina event likely to develop later this year, and an African Standing Wave likely to develop and enhance the West African Monsoon. With El Nino expected to be out of the picture, the risk for hurricane threats in the Caribbean, Gulf of Mexico and United States East Coast is likely to be higher than it was in 2023. That being said, predicting which areas are at the greatest risk at this long lead time is practically impossible. Residents in hurricane-prone areas should have a hurricane plan ready once the season starts, as it appears a very active season is probable in the Atlantic basin.

Atlantic Sea Surface Temperatures

Currently, the Atlantic sea surface temperature anomaly pattern resembles the classic positive (warm) phase of the Atlantic Multidecadal Oscillation (AMO). Over the past month, sea surface temperatures in the tropical Atlantic and eastern subtropical Atlantic have been well above average, while sea surface temperatures in the western subtropical Atlantic have been slightly below average and sea surface temperatures in the far north Atlantic have been slightly above average. Sea surface temperatures in the Atlantic Main Development Region (MDR) have been at or exceeding record warm levels for most of the past year. While there has been some slight anomalous cooling in recent weeks and climate models suggest some additional cooling is possible before the peak of the season, the tropical Atlantic is likely to remain much warmer than normal through the peak of the Atlantic hurricane season. This sea surface temperature anomaly pattern favors a very active Atlantic hurricane season, especially in the deep tropics including the Caribbean Sea. Overall, this is arguably the most favorable sea surface temperature anomaly pattern in the Atlantic basin in recent years from this lead time.

El Niño Southern Oscillation (ENSO)

El Niño conditions continue over the equatorial Pacific, though the event is gradually weakening. The latest weekly Niño 3.4 value was +1.3°C, which still is considered a moderate El Niño. However, the eastern equatorial Pacific has cooled more rapidly, and the Nino 1+2 region weekly value went negative (-0.1°C) for the first time in over a year this week. The 90-day Southern Oscillation Index average was -2.97, which is indicative of weak warm-ENSO conditions, and in the last 30 days it has risen to positive levels – a sign the El Niño atmospheric response is slowly starting to decay. Negative sea surface temperature anomalies have gradually strengthened in the equatorial Pacific, and there is almost no warmer than normal water left for the El Niño event to persist much longer. Therefore, continued weakening of El Niño is expected, and ENSO should return to neutral around May. With the developing subsurface cool pool, it appears likely that La Niña should develop before the peak of the Atlantic hurricane season. The current CPC-ENSO probabilistic forecast gives an 82% chance of La Niña conditions for the August-September-October (ASO) trimonthly period, a 17% chance of ENSO-neutral conditions, and only a 1% chance of El Niño conditions. La Niña years typically have reduced vertical wind shear in the deep tropical Atlantic, especially the western MDR and Caribbean Sea. The expected ENSO pattern for 2024 is expected to be highly conducive for hurricane development in the Atlantic basin, as La Niñas also typically result in large-scale subsidence over the central and eastern Pacific Ocean.

West African Monsoon & Model Predictions

During most recent hurricane seasons, the West African Monsoon has been stronger than normal, favoring enhanced predicipation in the Sahel region of Africa. With near record-warm sea surface temperatures over the tropical Atlantic and an expected La Nina, it is likely that convection will be enhanced over Africa and the Indian Ocean, a favorable setup for tropical wave development. The NMME model guidance also gives very high probabilities of above-average precipitation over the tropical Atlantic and Caribbean; which is also suggestive of a conducive environment for hurricane development. This is in contrast to last year, when the NMME guidance predicted below-average precipitation in the Caribbean (a common feature of El Niño events).

Cyclonic Fury’s 2024 Atlantic hurricane season forecast

• 17-24 named storms (1991-2020 average: 14.4)
• 8-12 hurricanes (1991-2020 average: 7.2)
• 4-7 major (Category 3+) hurricanes (1991-2020 average: 3.2)
• Accumulated Cyclone Energy 180 (+/- 50) (1991-2020 average: ~122)

This is the highest seasonal forecast Cyclonic Fury has ever issued in March. Cyclonic Fury also gives the following probabilities of activity:

• Hyperactive season: 50% (Accumulated Cyclone Energy (ACE) of 160 or greater) – With near-record tropical Atlantic warmth, a La Nina likely to develop over the equatorial Pacific by the peak of the season, and a strong West African Monsoon expected, a hyperactive season is currently the most likely scenario.
• Above normal season: 35% (Accumulated Cyclone Energy (ACE) of 126-159) – This could occur if the tropical Atlantic anomalously cools before the peak of the season, but environmental conditions remain generally conducive.
• Near normal season: 10% (Does not fall into the Below Normal, Above Normal or Hyperactive criteria) – This is an unlikely scenario, and would likely only be plausible if the tropical Atlantic significantly anomalously cools before the peak of the season and La Niña fails to develop.
• Below normal season: 5% (Accumulated Cyclone Energy (ACE) of 73 or less) – This is an extremely unlikely scenario, and would only be plausible through an unexpected event similar to the Thermohaline Circulation collapse in 2013. Regardless, there is always uncertainty in forecasting a hurricane season this far out.

This is the seventh straight year Cyclonic Fury has issued a pre-season Atlantic hurricane forecast, with the forecast typically being released in late March (with the exception of 2023, when it was released in early April). In 2018, in our March forecast, Cyclonic Fury predicted 11-16 named storms, 5-9 hurricanes, 2-4 major hurricanes, and an Accumulated Cyclone Energy (ACE) of 125 units. This forecast verified quite well, as 15 named storms, 8 hurricanes, and 2 major hurricanes formed, with an ACE index of 133. In 2019, our March forecast was much less accurate, as Cyclonic Fury predicted 8-13 named storms, 3-6 hurricanes, 1-3 major hurricanes and an ACE index of 80. Actual activity was significantly higher, as El Niño dissipated sooner than expected, with 18 named storms, 6 hurricanes, 3 major hurricanes, and an ACE index of 132. In 2020, our March forecast correctly anticipated potential for an active season, as we predicted 13-18 named storms, 6-10 hurricanes, 2-5 major hurricanes with an ACE index of 140 units. However, our forecast was too low in every category since record-breaking activity occurred. In 2021, our March forecast once again correctly anticipated an above-average hurricane season, predicting 14-19 named storms (actual: 21), 6-9 hurricanes (actual: 7) and 2-4 major hurricanes (actual: 4), and an ACE index of 135 units (actual: 146). Our forecast was a bit too low in named storms and ACE, but overall, the forecast was fairly accurate. In 2022, our March forecast overestimated the actual activity, predicting 15-20 named storms (actual: 14), 6-9 hurricanes (actual: 8), 3-5 major hurricanes (actual: 2), and an ACE index of 130 units (actual: 95). The near-average activity was significantly less than the above-average season that was anticipated. In 2023, our April forecast significantly underestimated the actual activity, predicting 11-14 named storms (actual: 20), 4-6 hurricanes (actual: 7), 1-3 major hurricanes (actual: 3), and an ACE index of 75 units (actual: 146). The forecast bust is attributed to the tropical Atlantic undergoing significant warming to record-warm levels prior to the start of the season, which significantly enhanced hurricane activity in 2023 beyond normal levels associated with El Niño.