The 2022 tropical cyclone season…near normal tropical cyclones but below normal major hurricanes and ACE index.
Fig. 1: The 2022 North Atlantic basin preliminary tropical cyclone tracks.
Discussion: The seasonal totals of tropical cyclone activity for the North Atlantic basin during the 2022 season was 14 tropical storms, 8 hurricanes and 2 major hurricanes. The accumulated cyclone energy (ACE) index was 95.1. The observed totals are very close to normal while ACE index was 78% of normal. The ACE index is the smallest seasonal total since 2015 (63) and only the 5th year of the past 15 to stay <100. The number of tropical storms (14) is the smallest seasonal amount since the 2015 El Nino year (11).
The strongest (max wind 135 knots) storm of 2022 was Category-4 Major Hurricane Ian which produced widespread destruction and 100’s of fatalities across southwest to east-central Florida in late September. Interestingly, the lowest pressure was produced by Category-3 Major Hurricane Fiona at 932 MB just to the east of the Bahamas in mid-September. Almost all of the seasonal intensity as identified by ACE index was produced by Hurricane Danielle (12.5), Hurricane Earl (14.2), Major Hurricane Fiona (26.3), and Major Hurricane Ian (17.4).
The 2022 tropical cyclone season is most notable due to Category-4 Major Hurricane Ian. Ian was the deadliest hurricane to strike Florida in 87 years. The most dramatic impact of this storm was a 10-15 foot storm surge striking Fort Myers and Naples area. The hardest hit areas were Sanibel Island and Pine Island where numerous structures were heavily damaged or destroyed. About 6 weeks later, sprawling minimal hurricane Nicole struck the East Coast of Florida near West Palm Beach (and then inland to areas struck by Ian) also producing widespread damage mostly due to high seas and storm surge. Nicole was only the 3rd hurricane to make landfall on the Florida Coast during November. In fact, the 2022 season produced a rare 3 November hurricanes.
The 2022 season was also notable due to the lack of early season activity, especially in August when no tropical cyclones formed. The North Atlantic basin failed to produce a tropical storm from July 3 to August 31, a record 59 days. The presence of a tropical upper tropospheric trough (TUTT) over the Western Caribbean Sea was a leading inhibitor of tropical cyclone activity at that time. However, dramatic warming of tropical North Atlantic index (a record +0.663 in September) and weakening of the TUTT allowed 10 tropical cyclones to form mostly after the peak of season (Sep. 10th).
The 2022 season featured a strong La Nina climate and eventually a very warm North Atlantic basin all of which was anticipated by seasonal forecasts issued last spring and early summer. However, presence of the TUTT pattern was not expected and consequently very robust seasonal forecasts were too robust compared to the observed values.