![]() ![]() So how does the El Niño currently look in nature? To see that, we need to look at the ocean surface temperatures and how warmer/colder they are from the long-term average (anomaly).īelow you can see the latest ocean anomalies across the Pacific Ocean. Through this ocean-atmosphere system, the ENSO influences the weather globally. This way, ENSO has a strong impact on the tropical rainfall and pressure patterns, affecting the ocean-atmosphere feedback system. At the same time, the air is descending in the western Pacific, causing stable weather and high-pressure conditions. Rising air in the eastern Pacific causes more storms and precipitation and lowers the pressure over that region. The following image below from NOAA Climate shows the typical circulation during an El Niño event, which will be the dominant phase for the next ten months at least. But it is usually more influential during the peak of its phase in Fall and Winter. We can observe a global shift in pressure patterns during the emergence of an ENSO phase. These pressure changes translate into global circulation over time, affecting seasonal weather over both Hemispheres. But during a La Niña, the pressure over the equatorial Pacific rises, creating stable conditions and fewer storms. Besides the ocean temperatures, one of the main differences between the phases is the pressure patterns they promote, seen below as high (H) and low (L) pressure zones.ĭuring an El Niño, the pressure over the tropical Pacific drops, with more rainfall and storms in this region. The cold ENSO phase is called La Niña, and the warm phase is called El Niño. It then lasts until Spring, but some events can last up to two or three years. This affects the overall global circulation over time, changing the weather patterns worldwide.Ī (cold/warm) phase usually develops between late Summer and early Fall. This is where the main strength of a warm/cold event is calculated from.Įach ENSO phase influences the pressure and weather in the tropics differently. The main region is seen in the image as the Nino 3.4 region. ![]() Regions 3 and 4 expand over the east and west tropical Pacific. The image below shows the ENSO regions across the tropical Pacific. Typically there is a phase change around every 1-3 years. You will see how El Niño is currently growing and how it is expected to influence the upcoming cold weather season of 2023/2024.Įl Niño is a warm phase of the ENSO, which stands for “ El Niño Southern Oscillation.” This region of the equatorial Pacific Ocean regularly shifts between warm and cold phases. That is especially true during the Winter season when the pressure systems are strongest.Īn El Niño event can also be used as an indicator, not just the cause, as it tells us what the current state of the atmosphere is that produced it in the first place. Ocean anomalies have long been known to play an important role in atmospheric circulation and our weather on smaller and larger scales. A strong El Niño event is expected to develop, with weather impacts spreading across the United States, Canada, and Europe in the Fall and Winter 2023/2024 seasons. Based on the latest data, NOAA has released an El Niño advisory showing a rapidly growing El Niño anomaly. ![]()
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