El Nino Forecast to Intensify Into 2027, Bringing Increased Winter Flight Turbulence

The World Meteorological Organisation (WMO) has forecast that a very strong El Niño climate pattern will intensify in the coming months and persist into early 2027. This development is expected to have widespread effects on global aviation and air travel during the winter season. Airlines could face more unpredictable weather conditions, which may lead to increased clear-air turbulence, flight delays, and alterations to jet streams and flight times.

According to turbulence and PIREP platform SkyPath, El Niño changes wind shear in the upper atmosphere, which is the primary driver of clear-air turbulence. This type of turbulence is particularly hazardous as it is invisible and cannot be detected by weather radar. SkyPath noted that atmospheric data spanning 40 years shows wind shear at aircraft cruising levels over the North Atlantic Ocean increases by approximately 35% when transitioning from a very strong La Niña to a very strong El Niño. Furthermore, SkyPath reported that turbulence over the North Atlantic has already increased by about 30%.

The impact of El Niño on flight conditions varies by region. SkyPath's analysis indicates that stronger wind shear and elevated turbulence probabilities are anticipated over the United States, South America, Southeast Asia, Australia, and Africa. However, the phenomenon has the opposite effect in East Asia, where El Niño is associated with a decrease in wind shear and turbulence, while La Niña increases them.

This climate pattern occurs alongside a longer-term trend of rising clear-air turbulence. A peer-reviewed study published in Geophysical Research Letters analyzed atmospheric data from 1979 to 2020. Conducted by researchers from the University of Reading and the Met Office, the study found that at an average point over the North Atlantic, the annual duration of severe-or-greater clear-air turbulence at cruising altitudes increased by 55%, rising from 17.7 hours in 1979 to 27.4 hours in 2020.

Additionally, El Niño is expected to alter the position and strength of global jet streams by changing tropical heating and atmospheric circulation. During such events, the strongest portions of the jet stream typically shift south and extend farther east across the North Pacific Ocean, bringing the jet stream closer to North America, which can impact flight paths and durations.