Hurricane researchers at Colorado State University are working to temper expectations for what could be a record-breaking year, but they are not yet ready to raise the white flag and signal an early end to the season.

On Tuesday, Dr. Phil Klotzbach, a hurricane specialist at CSU, said he expects tropical cyclone activity in the basin to remain normal or below average through at least Sept. 16. The chance of above-average activity in the next few weeks is only 10%, as the basin remains in a state of record-breaking inactivity.

In fact, the period without tropical activity from August 12 to September 3 was the quietest period in tropical weather evolution in 56 years, and the basin is now beginning to fall behind key indicators of an average season.

Tropical Weather Outlook in the Atlantic September 3, 2024

(FOX Weather)

By September 4, an average season would have produced seven named tropical storms, two hurricanes and one severe cyclone.

So far in 2024, the basin has seen five named storms, three hurricanes, and one major hurricane. However, with little activity expected over the next two weeks, the basin is unlikely to reach the level of activity that a typical year produces.

“So what has been preventing storms over the last few weeks? I think the big issue has been the position of the monsoon trough over Africa,” Klotzbach told FOX Weather. “We’ve had anomalous cooling in the Gulf of Guinea, coupled with a trend toward Atlantic Nina (although we may not officially meet the definition). Because of that, we have a strong equatorial (sea surface temperature) and sea level pressure gradient that helps push the monsoon trough too far north when looking for hurricane activity.”

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What’s going on with the tropics?

Meteorologists point to at least four different elements that affect activity: the location of the monsoon trough over Africa, cooler waters in the eastern Atlantic, significantly higher temperatures in the upper layers of the atmosphere and abundant dry air on the eastern edge of the basin.

Computer models do not readily account for these deviations from the norm. They have likely offset favorable circumstances such as reduced vertical wind shear, near-record sea surface temperatures, an enhanced African monsoon, and the emerging La Niña status of the El Niño-Southern Oscillation.

Against this background, the most important and only question that remains is whether favorable conditions will prevail in the pool again or whether the season is actually over.

“I think it’s too early to call the season off,” Klotzbach explained. “The latest EPS ensemble is more robust in terms of upcoming Atlantic tropical cyclone activity. As we mention in our two-week forecast, the current National Hurricane Center area in the Caribbean bears watching once it reaches the Gulf of Mexico. In addition, a strong easterly wave appears to be moving away from Africa in about a week. It’s too early to know what will happen to this system, but overall, conditions for its intensification are looking pretty good right now.”

With 14 named storms, seven hurricanes, and three major hurricanes, it is still possible for activity to return to normal levels this season, but levels significantly above the average seasonal activity level seem out of reach.

It is important to remember that a normal season can have just as big an impact as a year with above-average activity.

The 2022 season was considered a nearly normal season with 14 named storms, eight hurricanes and two major storms, but saw Hurricane Ian, making the year the third costliest in history.

In contrast, the 2023 season was considered above average with 20 named storms, but had the least impact on the United States in a decade.

Cool water in the eastern Atlantic

(NOAA)

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Tropical activity declining in much of the world

In their latest update, the researchers failed to mention that activity worldwide is at a record low despite record-high sea surface temperatures.

In other words, this is not just a one-off year in the Atlantic; the Indian and Pacific Ocean basins are also similarly affected by widespread inactivity.

The overall decline in activity is nothing unusual, as tropical weather experts, including Klotzbach, have long pointed out that overall tropical cyclone activity is declining worldwide, particularly in the western Pacific.

“By examining global TC activity from 1990 to 2021, we find significantly decreasing trends in the number of hurricanes and ACE, largely due to a significantly decreasing trend in the western North Pacific,” the researchers explained in the 2022 report. However, the report says that cyclones that do form are becoming more costly and more prone to rapid intensification.

It remains to be seen whether the dramatic decline in tropical cyclone activity around the globe is a harbinger of less impactful years to come or whether it is simply an exceptional year.

Hurricane season lasts until November 30 in the Atlantic and eastern and central Pacific, but hurricane activity can occur year-round in basins such as the western Pacific.