The El Niño weather phenomenon has continued to strengthen over the past month and is anticipated to intensify further through the end of the year, according to the US National Oceanic and Atmospheric Administration’s Climate Prediction Center (CPC). The CPC now forecasts a more than 90% chance of a very strong El Niño event occurring during the Northern Hemisphere fall and winter seasons.
Specifically, the period from September to February is expected to experience particularly strong El Niño conditions. The Climate Prediction Center has estimated a 75% probability that the event between October and December could reach historic levels, potentially surpassing the intensity of any El Niño recorded since 1950.
Understanding the Intensity of El Niño
For an El Niño to be classified as 'very strong,' the El Niño-Southern Oscillation (ENSO) index typically needs to exceed 2 degrees Celsius. Current projections suggest that during this upcoming period, the index could climb above 2.5 degrees Celsius, indicating an exceptionally powerful event.
However, the CPC cautions that a stronger El Niño does not automatically lead to proportionately more severe weather impacts. While the intensity increases the likelihood of certain weather patterns and their potential effects, the exact outcomes can vary.
Signs of Strengthening
Scientific observations reinforce the forecast of a rapidly strengthening event. Sea surface temperature anomalies in the eastern equatorial Pacific have exceeded 3 degrees Celsius over the last month, with subsurface waters also registering significantly warmer than average. Atmospheric indicators, including unusual westerly winds and increased rainfall over the central and eastern Pacific, further confirm the intensifying El Niño.
Global and Regional Impacts
The CPC’s forecasts for El Niño-Southern Oscillation probabilities indicate the highest chances for a very strong event from September-November through November-January, with a gradual decline thereafter. For regions like India, a strong El Niño is generally associated with hotter and drier conditions, contrasting with La Niña, which typically brings more favorable rainfall.