Experts Forecast a Very Active 2024 Hurricane Season, Largely Due to Record Sea Surface Warmth
Michelle Milliken
Colorado State University hurricane experts have been predicting the intensity of hurricane season for 40 years, and their latest forecast calls for a very active Atlantic hurricane season in 2024.
CSU issued its April forecast last week, a tradition dating back to 1995, though they’ve been issuing forecasts in general since 1984. The forecast writers say that with record sea surface warmth in the tropical and eastern subtropical Atlantic, along with an expectation that the tropical Pacific is expected to shift from El Niño to La Niña conditions by peak hurricane season (August through October), they’re predicting a season 170% more active than usual. Their current best estimates, as these reports are, call for 23 named storms during the full season (June through November), 11 of which will become hurricanes. Of those, five are expected to reach at least Category 3 strength with sustained wind speeds of 111 miles per hour or higher.
To compile these forecasts, the CSU team uses a statistical model, along with four models from the European Centre for Medium-Range Weather Forecasts, the Centro Euro-Mediterraneo sui Cambiamenti Climatici, the UK Met Office, and the Japan Meteorological Agency. Those models look at factors including past hurricane season statistics, Atlantic sea surface temperatures, sea level pressures, vertical wind shear levels, and El Niño.
Though the April reports tend to be less precise than those that come out later in the year, the researchers came to their prediction of 11 hurricanes – their highest April prediction ever – because of current and forecast conditions that create the ideal environment for hurricane development and intensification. That includes warmer Atlantic sea level temperatures in the spring, which tends to promote a weaker subtropical high and light winds across the tropical Atlantic. With such conditions, surface temperatures usually remain higher into peak hurricane season. These warmer temperatures themselves fuel hurricanes, but the warmth also leads to lower atmospheric pressure and an unstable atmosphere, which are also ideal for hurricanes.
Conditions in the Pacific can also contribute to storms. The team says by the time we reach peak Atlantic hurricane season, the tropical Pacific is expected to shift from its current El Niño pattern to La Niña, which usually means decreased upper-level westerly winds through the Caribbean and into the tropical Atlantic. This can lead to lower vertical wind shear, another helpful ingredient in hurricane development and intensification.
While changing conditions could make the April forecast a little less reliable, the team believes there’s slightly less uncertainty this year.
Phil Klotzbach, lead author and senior research scientist in CSU’s Department of Atmospheric Science, says, “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.”
There will be more forecasts issued on June 11, July 9, and August 6.
While this season’s current prediction is 170% of usual activity, last year’s finished up at 120%. The most significant hurricane was Idalia, which hit land at Category 3 intensity. This year, the report calls for a 62% chance of a hurricane making landfall somewhere along the U.S. coastline.
