Hurricane activity has paused. Here’s when it may come back to life.
Hurricane season roared to life in late June and early July as Beryl became the earliest Category 5 on record. Since then, however, the Atlantic has been bereft of tropical activity, and the National Hurricane Center doesn’t anticipate storm development for at least a week.
Considering all of the forecasts for a very active season – Colorado State University upped its forecast to 25 total named storms just two weeks ago – an understandable question would be: Where are the hurricanes?
The short answer is that they’re still coming and that the current break in activity isn’t unexpected or unusual. It could well be the calm before the storm.
Hurricane season doesn’t peak until Sept. 15 on average, with activity often lasting well into November. Moreover, the weather patterns expected to help fuel an active season are just starting to take shape.
A burgeoning La Niña weather pattern will favor more upward-moving air across the Atlantic, enhancing the number of storms that can form. It will also help promote weaker-than-normal upper-level winds that favor increased storm organization. Meanwhile, record-warm water temperatures will provide ample fuel to make storms stronger.
Where this season stands so far
Storm activity so far this season is actually running ahead of average, despite the recent hiatus. A season’s first named storm forms on average around June 20; this year, Alberto formed on June 19. By Aug. 3, two storms have typically developed. Three have already formed this year, though Chris was a marginal storm that lasted only about 12 hours.
Also of note: A season’s first hurricane doesn’t usually materialize until Aug. 11, and a Category 3 or stronger hurricane until Sept. 1. Yet Beryl became a hurricane on June 29 and an “extremely dangerous Category 4 hurricane” on June 30.
What’s next?
It’s usually around the second or third week of August when the oceans really begin to crank out storms. That’s when they are most numerous in the Main Development Region, the zone between the west coast of Africa and the eastern Caribbean where most long-track hurricanes form.
The hot, dry air associated with an outbreak of dust from the Sahara desert is suppressing the growth of tropical systems. By some estimates, the ongoing outbreak of Saharan dust has been the most prominent since June 2022. The dust should become less of an impeding factor as we enter August.
It’s probable the outbreak in dust is tied to the sinking motion of several large overturning atmospheric waves traversing the equatorial regions. Meteorologists call these convectively coupled Kelvin waves. Each one tends to affect the atmosphere for a week or so.
Meanwhile, there’s an even larger-scale overturning wave in the atmosphere called the Madden-Julian Oscillation, or MJO. It’s essentially a large area of thunderstorms that drifts eastward across the global tropics. When the rising phase passes over the Atlantic, hurricanes can more easily form.
In recent weeks, the MJO’s sinking phase has been centered over the Atlantic. That helps explain the lack of storms. By around the second week of August, more rising air conducive to thunderstorm development is expected to move over the Atlantic.
By then, the oceans will have heated up even more, and the emerging La Niña will have established firmer footing. It’s possible that storm activity may increase substantially by the back half of August.
During this lull in storm activity, it’s a good time to review hurricane-readiness plans, especially if you live in a vulnerable zone.