2024 hurricane season: outlook upped from ‘very active’ to ‘hyper active’
The North Atlantic could deliver a “hyper-active” hurricane season with activity levels about 78% above the 1991-2020 averages and including 3 US landfalls, the UK government-supported research venture Tropical Storm Risk (TSR) has said in a major upgrade to its prior forecasts for the year.
What looked “very active” in the December tea leaves seems “hyper-active” today as TSR upped its forecast for 2024 accumulated cyclone energy (ACE) to 217, 35% above a preliminary guess made in December 2023 and 78% over the 30Y average. ACE is a composite reading capturing the frequency, intensity and duration of named storms throughout the season.
Warm surface water temperatures will dovetail with a global shift to La Niña conditions to bear a “strong enhancing influence on the upcoming Atlantic hurricane season,” researchers wrote. Warm water supports storm convection; La Niña reduces storm-shredding wind shear.
While “uncertainties remain” and the overall confidence level is listed between 0 and 5% across metrics, key ingredients for an active season appear locked in place. TSR cites “high confidence” of both a weak to moderate La Niña and of sea surface temps “much warmer than average”.
“With the primary climate factors very likely to be strongly enhancing for hurricane activity in 2024, the confidence in the forecast for a very active season is higher than what the low skill scores would imply,” authors wrote.
TSR gives an 83% probability that the 2024 season will end in the upper third of the 30-year track record, a 16% chance of hitting the middle third and a mere 1% chance of blowing over into the bottom tercile.
By the numbers, TSR expects 22 named storms, including 11 hurricanes and five intense hurricanes for the full North Atlantic. That's up from the 20 named storms, nine hurricanes and four intense hurricanes TSR estimated back in December.
Likewise, for the five storms including three hurricanes considered likely to make a US landfall, the ACE reading could end up some 70% above the 30-year averages, TSR indicated.
The forecast season may be young, but the early consensus looks tight. Researchers at Colorado State University said late last week it expects a “very, very busy” season and, like TSR, offered forecasts 50-75% above the 30Y averages including a 71% overshoot for ACE at 210. Researchers called the combination of La Nina and warm water temps the “optimal pattern” for a busy season.
Did you get value from this story? Sign up to our free daily newsletters and get stories like this sent straight to your inbox.
