Atlantic hurricane season forecast: 2025 predicted to be 'above average'

BBC News

22-05-2025

US weather experts are warning that the 2025 hurricane season could have an 'above average' number of storms.In the latest official forecast just released, the National Oceanic and Atmospheric Administration (NOAA) predicts that the 2025 storm season could have between 13-19 named storms, of which six to ten could be hurricanes and three to five of those could be major hurricanes of Category 3 (111mph) or above.Hurricanes can be deadly and devastate communities so each year US forecasters try to predict what the season ahead will be like, helping those in hurricane-prone areas to prepare early, stay across warnings and hopefully prevent loss of life. The North Atlantic Hurricane season runs from 1 June to 30 November.This forecast will be updated as the season unfolds.
What is a 'normal' hurricane season?
Hurricanes are tropical storms that form over the North Atlantic Ocean and Northeast Pacific. In other bits of the world these powerful storms are known by different names - typhoons in the Far East close to places like China and Japan and cyclones in the Indian Ocean.Hurricane season activity usually peaks in September. Forecasters use weather observations, decades of historical data and run computer models to predict how the season might behave.An "average" one, based on a 30-year period from 1991-2020, produces 14 named storms.If the number of hurricanes forecast is higher than average these are referred to as active or hyperactive seasons - while other years bring fewer storms, and are known as less active seasons.Another annual forecast, released slightly earlier by Colorado State University, points to 2025 being an above-average season, with a total of 17 named storms predicted, including nine hurricanes and four of those becoming major hurricanes.
How accurate was last year's forecast?
The 2024 hurricane season, overall, was correctly predicted by NOAA to be more active than average. There were 18 named storms, 11 hurricanes and five major hurricanes; it was also the first in five years to feature multiple Category 5 hurricanes (the highest level). Yet it also defied expectations at times, with stretches of powerful storms interspersed with weeks of relative calm.It started as a record breaker. In June and July, Hurricane Beryl devastated parts of the Caribbean and broke records as the earliest storm ever to reach Category 5 - an intensity usually seen during peak season. It brought death and destruction to parts of the Caribbean, areas of Mexico and the Gulf coast of the US.Whilst concern grew about what might be to come, the season then became unusually quiet midway through with the the most prolonged lull in hurricane numbers for around 50 years.
It wasn't until late September and into October that the big ones returned.Category 4 Hurricane Helene made landfall in Florida's Big Bend, bringing powerful winds and later record-breaking rainfall across the Carolinas. Hurricane Milton, which reached Category 5 strength near the Yucatán Peninsula, struck Florida as a Category 3, driving hurricane-force winds far inland.The human cost across the season in terms of deaths was in the hundreds with most of the fatalities being water-related, from flooding, storm surges and rip currents. In terms of the physical damage, estimates varied widely depending on the scope of impacts considered, but according to NOAA direct physical damage from Helene cost $78.7bn and Milton $34.3bn, external.
How is a hurricane season forecast?
Each year the areas just north and south of the Tropic of Cancer and Capricorn spawn storms that vary in the paths they take and the force with which they strike land in the Caribbean, Central America or the US. Hurricanes draw energy from the tropical Atlantic, so forecasters monitor the sea surface temperatures well ahead of the season.In 2024, early signs of above-average warmth in that area suggested a higher risk of frequent and intense storms. This year, while many areas remain warmer than average, there are also large regions where the temperature is slightly cooler - or even below normal. It could be an early sign that there may be less energy available for hurricane development.However, forecasting an entire hurricane season is a complex challenge, as it involves many interconnected factors, one significant one is the West African monsoon.These rains that bring powerful thunderstorms to Nigeria, the Ivory Coast and Sierra Leone can sometimes develop into hurricanes once they move across the Atlantic.If the West African monsoon behaves differently to usual, it can significantly influence how and when hurricanes form.
In addition, complex wind patterns that stretch from Africa to the Gulf of Mexico can either support or hinder hurricanes.The ideal environment for a hurricane to develop is a moist atmosphere with steady winds.Any sudden shifts in wind direction and speed - known as wind shear - can tear developing tropical storms apart before they can fully form into hurricanes.Forecasting wind shear for an entire season is extremely difficult, but forecasters had expected optimal conditions for hurricanes in 2024. In reality there were periods when wind sheer hindered hurricane formations across parts of the Atlantic and Gulf of Mexico and this may have contributed to the mid-season lull.
Influence of El Niño and La Niña
The infamous El Niño, and its opposite La Niña weather patterns, strongly influence wind patterns over the Atlantic despite occurring many thousands of miles away.Powerful rainstorms that develop over the warm waters of the eastern Pacific during El Niño often lead to increased wind shear over the Gulf of Mexico, Caribbean, and tropical Atlantic. The opposite tends to occur during La Niña, when wind shear is typically reduced. Since wind shear is one of the most effective forces for tearing hurricanes apart, understanding conditions in the eastern Pacific is crucial for forecasting. Projections for 2025 suggest a neutral pattern - neither El Niño nor La Niña - which makes predicting wind patterns more challenging and uncertain.