CSU Researchers Forecast Extremely Active Atlantic Hurricane Season

Posted on April 5, 2024

Meteorologists from Colorado State University (CSU) are forecasting an extremely active Atlantic hurricane season. Their 2024 forecast includes 23 named storms, 11 hurricanes, 5 major hurricanes, 115 named storm days and 13 major hurricane days.

This forecast is way above the average - 23 named storms compared to 14.4 on average for 1991 through 2020. As Axios notes this is the highest number of hurricanes this group of researchers has ever forecast for an Atlantic hurricane season. They are forecasting 11. Their previous high forecast has been nine.

The researchers cite warm tropical and eastern subtropical Atlantic sea surface temperatures for their 11 hurricane prediction.

When waters in the eastern and central tropical and subtropical Atlantic are much warmer than normal in the spring, it tends to force a weaker subtropical high and associated weaker winds blowing across the tropical Atlantic. These conditions will likely lead to a continuation of well above-average water temperatures in the tropical Atlantic for the peak of the 2024 Atlantic hurricane season. A very warm Atlantic favors an above-average season, since a hurricane’s fuel source is warm ocean water. In addition, a warm Atlantic leads to lower atmospheric pressure and a more unstable atmosphere. Both conditions favor hurricanes.

The CSU team also expects El Niño conditions to transition to more favorable La Niña conditions by the peak of the Atlantic hurricane season from August to October. The researchers note this tends to result in reduced vertical wind shear on developing systems.

While the tropical Pacific is currently characterized by El Niño conditions, these are likely to transition to La Niña conditions by the peak of the Atlantic hurricane season from August to October. La Niña tends to decrease upper-level westerly winds across the Caribbean into the tropical Atlantic. These decreased upper-level winds result in reduced vertical wind shear, favoring Atlantic hurricane formation and intensification.

The researchers gave a list of five analog seasons: 1878, 1926, 1998, 2010 and 2020.

Phil Klotzbach, senior research scientist in the Department of Atmospheric Science at CSU and lead author of the report, says in a statement, "Our analog seasons were all very active Atlantic hurricane seasons. “This highlights the somewhat lower levels of uncertainty that exist with this outlook relative to our typical early April outlook."

The report (PDF) also includes the following hurricane landfall probabilities:



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