ORLANDO, Fla. – ‘Tis the season for those seasonal hurricane forecasts to be released. Of the 12 seasonal forecasts released to date, all predict an above-average season.
Colorado State University, one of the most respected seasonal tropical forecast entities, just released its most active initial forecast. AccuWeather is predicting an ”explosive” season.
La Niña, forecast for the 2024 hurricane season, tends to lead to a more active hurricane season by promoting thunderstorm development in the Atlantic and reducing detrimental wind shear. Water temperatures are also already running way above normal. That combination is pointing to an extremely active upcoming hurricane season.
But what could throw a wrench into these hyperactive forecasts?
1. Saharan Dust
The yearly-occurring phenomena won’t completely shut down the season, but it could help to deter tropical development. There is a large dust outbreak currently impacting parts of southern Europe and the Canary Islands. The Saharan Air Layer, as it is known, is made up of dry, dusty and hot air. All of these things are detrimental to tropical systems.
The Bermuda high can steer the dust across the Atlantic and toward the U.S. This entity is also responsible for steering the storms themselves, so the further west the Bermuda high is, the higher the threat to the Caribbean and the U.S.
Typically, dust is most prolific early on in the hurricane season and fades by the peak of hurricane season.
If dust is around and is ingested into a storm, it could choke it out and keep it weak.
2. Water Temperature
This is a double-edged sword. Warm water fuels tropical systems. Currently, the Atlantic, especially the Main Development Region between Africa and the Caribbean, is running much above normal in the temperature department.
While the excess warmth in that region could help to get storms strong early, it may also help to steer them away from land. Generally, a strong storm east of the Lesser Antilles will have a higher tendency to curve away from the U.S. and Caribbean.
There are exceptions, however. Hurricane Irma in 2017 was exceptionally strong early and continued west to eventually impact Florida. A strong and expansive Bermuda high can still force storms west and get them closer to land.
This could still lead to an above-average season but could also mean more storms staying over the open Atlantic.
3. Sea surface temperature differences across Atlantic
While the Main Development Region of the Atlantic is warmer than normal, portions of the subtropics near Bermuda are a little cooler than normal. This difference in temperature could help to induce more wind shear than what would otherwise be expected during La Niña.
La Niña typically reduces wind shear over the Atlantic. Wind shear acts to tear up storms keeping them weak or destroying them all together.
During La Niña, hurricanes are more likely to track through the Caribbean. If this happens, storms would tend to miss the potentially higher-than-expected wind shear north of the Bahamas, however.
On paper, the transition to La Niña from El Niño and already extremely warm water temperatures points to an extremely active season. But just like in sports, you have to play the game.
NOAA and the National Hurricane Center will release its outlook in late May.
Hurricane season officially begins June 1.
Colorado State will update its forecast June 11. There is a chance for the numbers to go up as the university went under most computer model guidance for the 2024 hurricane season.
It is important to remember that no matter how many storms form, it only takes one storm to make it a bad season.