In just over two months, the 2023 Atlantic hurricane season will begin. The 2022 season was somewhat quieter than recent seasons, but still was quite impactful. Since 2016, the Atlantic basin has had at least 14 named storms, 6 hurricanes and 2 major hurricanes each year, with not one below-average season during this timeframe. There is an increasing chance that streak could end this year as El Niño chances appear to be increasing for this summer and fall. El Niño events usually decrease Atlantic hurricane activity by leading to increased wind shear in the deep tropical Atlantic. However, other indicators for Atlantic hurricane activity may not be as hostile, with above-normal sea surface temperatures expected in the Atlantic basin during the peak of the season.

Atlantic Sea Surface Temperatures

Overall, the current Atlantic sea surface temperature pattern is somewhat favorable for an active Atlantic hurricane season. The Atlantic basin is currently in an ongoing high-activity era that began in 1995, though there have been several quiet hurricane seasons during this time period in El Niño years. The most noteworthy feature is significantly above-normal sea surface temperatures in the eastern tropical and subtropical Atlantic. Above-normal sea surface temperatures in this region during Northern Hemisphere spring has been common during recent years, and is usually a favorable indicator for Atlantic hurricane activity. Climate models, such as the NMME model, are predicting this tropical Atlantic warmth to persist through the peak of the season. It is important to note that it is somewhat uncommon for El Niño years to have a warmer than normal tropical Atlantic, as warm-ENSO years often have an unfavorable sea surface temperature anomaly pattern in the Atlantic.

El Niño-Southern Oscillation (ENSO)

El Niño events, consisting of unusually warm waters along the equatorial Pacific and weak/reversed trade winds, usually develop over the equatorial Pacific every 2-7 years. Since mid-2020, ENSO has been consistently in the cool phase, with 2020-22 being three straight La Niña years. The Climate Prediction Center issued their final La Niña advisory in early March, and ENSO is currently considered to be neutral. There are serious indications that this cool ENSO phase is ending, and that El Niño is increasingly likely to develop before the peak of the 2023 hurricane season. The equatorial Pacific subsurface has rapidly warmed over the last few months, and is now much warmer than normal.

The CPC/IRI probabilistic forecast from early March estimated a 61% probability of El Niño for the peak of the Atlantic hurricane season (August/September/October), with a 35% chance of ENSO-neutral and only a 4% chance of La Niña conditions. El Niño events typically result in increased vertical wind shear in the Atlantic deep tropics, especially in the Caribbean Sea. With significantly elevated El Niño probabilities, this is heavily weighted into our slightly below-average Atlantic hurricane forecast.

West African Monsoon

In most recent Atlantic hurricane seasons, an unusually strong West African Monsoon (WAM) has led to enhanced rainfall and stronger tropical waves in the African Sahel region. Typically, an El Niño pattern results in large-scale sinking motion over Africa, which would be a detrimental factor for Atlantic hurricane activity. However, despite this, the NMME climate model suite is showing an enhanced chance of above-normal precipitation over western Africa, as well as slightly enhanced probabilities of above-normal precipitation over the eastern tropical Atlantic and subtropical Atlantic. If this forecast verifies, it could be another enhancing factor for the 2023 Atlantic hurricane season. However, the NMME is also predicting well below-average precipitation in the Caribbean, which is consistent with El Niño conditions.

Cyclonic Fury’s April 2023 Atlantic hurricane season forecast

• 11-14 named storms (1991-2020 average: 14.4)
• 4-6 hurricanes (1991-2020 average: 7.2)
• 1-3 major (category 3+) hurricanes (1991-2020 average: 3.2)
• Accumulated Cyclone Energy 75 +/- 25 (1991-2020 average: 122.1/1951-2020 average: 96.7)

Cyclonic Fury also gives the following probabilities of activity. Right now, our forecast leans to below-average activity due to an enhanced chance of El Niño development. However, there is still a lot of uncertainty of the strength and timing of the potential event, as the Spring Predictability Barrier (SPB) has not been passed yet. Because of this, our forecast remains fairly uncertain, though it certainly appears likely 2023 will be quieter than the last seven seasons.

• Hyperactive season: 5% (Accumulated Cyclone Energy (ACE) of 160 or greater) This is a very unlikely scenario, and will likely only occur if El Nino does not develop at all while the tropical Atlantic remains much warmer than average.
• Above normal season: 15% (Accumulated Cyclone Energy (ACE) of 126-159) This is a possible, though unlikely, scenario if El Nino is slow to develop or remains very weak, while the tropical Atlantic is warmer than average.
• Near normal season: 30% (Accumulated Cyclone Energy (ACE) of 73-125) This is a plausible scenario, if a weak to moderate El Nino develops but not enough to shut down the Atlantic deep tropics entirely.
• Below normal season: 50% (Accumulated Cyclone Energy of 73 or below) This is the most likely scenario, and will probably occur if El Nino develops before the peak of the season and strengthens during the summer and fall.

This is the sixth straight year Cyclonic Fury has issued a pre-season Atlantic hurricane forecast, though it is our first time doing such in early April (from 2018-2022 it was released in late March). 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.