2024 hurricane season: the worst climate prediction ever?

Only 6 named storms so far, 17–25 predicted.

Cast your mind back to May 23 and a press release from NOAA predicting an above-normal hurricane season. They were quite definite that it would be a very active season, giving an 85% change of above-normal, 10% near normal and 5% below-normal. Specifically, it forecast a range of 17–25 named storms, 8–11 becoming hurricanes and 4–7 major hurricanes, adding that forecasters had a 90% confidence in these ranges. The University of Pennsylvania put out an even more dramatic press release, saying that Michael Mann predicted a record-breaking 33 named storms this season, the highest count ever projected.

The hurricane season goes from June 1 to November 30 and initially the omens were good. Near-record ocean temperatures in the North Atlantic, the development of La Niña conditions in the Pacific, slower Atlantic trade winds and less wind shear, all of which tend to favour the development of tropical storms.

The season started energetically. The first named storm was Alberto on June 19. Then came hurricane Beryl, which was an extremely rare June major hurricane. It was the earliest Category 5 hurricane, and only the second recorded in July. Then things quietened down. In August hurricane Debby arrived, and then Ernesto in mid-August, then it became very quiet until Francine in early September.

September 10 marks the peak of the season. This month should be the busiest period of the hurricane season. But so far there have been 6 tropical storms and 5 hurricanes, of which only Beryl was a major one. In fact August 12 to September 3 has been the quietest period of tropical activity in over 50 years.

So what happened as nature defied forecasts and confused experts? CNN asked, ‘What the heck is going on?’ It seems that this year’s hurricane activity predictions might be one of the worst climate predictions ever.

Of course, there is still time for the season to pick up, but that would require an extraordinary run of storms. So there has to be a reason for the season’s underperformance. Some have suggested that the troposphere is unusually warm, which could be making the Atlantic more stable, inhibiting thunderstorm growth despite record warm sea-surface temperatures. One region of the Atlantic near the equator has cooled rapidly, which may have affected West African monsoon production. Also the developing La Niña isn’t happening as fast as predicted. Overall though, the answer as to why, scientifically speaking, the season has been disappointing, is not known.

But don’t be fooled by the calm. Some forecasters, determined that the future will see more storms, absurdly say that this season is a ‘lens’ into the more volatile storm behaviour of the future. That’s not a fully justified viewpoint, as it’s unclear if a warming world will produce more hurricanes. It hasn’t so far.