A third-year event is forecast to develop over the Fall and Winter 2022/2023. You can see the first La Nina event in 2020 and a second-year La Nina in late 2021, lasting through the Winter. This way, we can use these anomalies as an “indicator” to know the current state of the global climate system.īelow, you can see the last years of ocean anomalies in the ENSO region. La Nina forms during strong easterly trade winds, which can tell us much about the general state of global circulation. That is the currently active La Nina entering its third-year phase. We can see the cold anomalies in the marked ENSO regions. Through this ocean-atmosphere system, the ENSO influence spreads globally.īelow we have a close-up view of the tropical Pacific Ocean surface analysis. This way, ENSO significantly impacts the tropical rainfall and pressure patterns and thus impacts the ocean-atmosphere feedback system. At the same time, the air is rising in the western Pacific, with a lot of rainfall and lower pressure. Air descends in the eastern Pacific, promoting stable and dry weather. The image below from NOAA Climate shows the typical circulation during a cold ENSO phase. With each new developing phase, large-scale pressure changes are observed in the tropics. We are currently in a La Nina phase, entering its 3rd year, which is a rather rare occurrence.ĮNSO significantly changes tropical rainfall, pressure patterns, and the complex exchange between the ocean and the atmosphere. The cold phase is called La Nina, and the warm phase is called El Nino. Typically there is a phase change around every 1-3 years. It will also play its role in the Winter.ĮNSO is short for “El Niño Southern Oscillation.” This region of the equatorial Pacific Ocean changes between warm and cold phases. It oscillates based on the temperature difference between the east and west Indian ocean. You can see the Dual Mode Index (DMI) on the left. This is one of the most well-known ocean oscillations, with an especially strong influence during Winter. Marked in the center is the El Nino Southern Oscillation or ENSO. Each has its role and significance in different areas and time scales. Looking at the latest ocean anomalies, we have marked a few regions we are currently watching for Winter 2022/2023 development. So it is very important to note that while the oceans can play their climate role directly, they are also changing due to the weather patterns. The key here is the word “two-way.” For example, we sometimes look at ocean anomalies and how they will influence our long-term weather, while the weather also influences ocean anomalies. This is a two-way system with influences going both ways on smaller and larger scales. In the image below, you can see the complex air-sea interactions. Oceans cover over 70% of the planet’s surface and play a significant role in the Earth’s climate system. Global weather is a very complex system, with many large-scale and small-scale climate influencers.īut how can the oceans have such an impact on winter weather? We will first examine what this La Nina is, how it works, and how it is predicted to change as we get closer to the Winter season of 2022/2023. To understand the Winter season, we must realize that there are many “drivers” of weather. Modifying the jet stream pattern over North America and the Pacific Ocean will also extend its reach to the rest of the world. It is currently cooling down and expected to continue into early Winter. It shows a growing influence of the third-year La Nina phase. September and October will be slightly cooler and drier than normal, on average.New forecast data is now released for Winter 2022/2023. The hottest periods will be in mid- to late July and early August. Summer will be warmer and wetter than normal. April and May will be warmer and slightly wetter than normal, on average. The snowiest period will be in mid-November. The coldest periods will be in mid-November and early and late December. Winter temperatures will be milder than normal, with slightly below-normal precipitation and snowfall. Enter Your Location Annual Weather Summary
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