Timeline of wet and dry conditions associated with La Niña On a more global scale, La Niña is believed to have contributed to flooding in eastern Australia this year and exacerbated drought in the United States and East Africa. Ethiopia, Kenya and Somalia are facing their worst drought in 40 years, with three years of La Nina likely to exacerbate severe drought in the Horn of Africa and create a humanitarian crisis. Scientists say such a long La Niña period is probably just a fluke, but some researchers predict that climate change could make La Niña-like conditions more likely in the future due to changes in ocean currents from fresh cold water from the melting of ice in polar regions. Changes in ocean currents could lead to a series of atmospheric pressure changes that lead to strengthening tropical Pacific trade winds – which ultimately lead to cooling of the central and eastern Pacific and thus La Niña conditions. An increase in La Niña conditions in the future will increase the likelihood of flooding in Southeast Asia and Australia. A flood-weary eastern Australia has said it expects more flooding in the coming months as La Nina continues. Elsewhere, continued La Nina conditions may expand the risk of droughts and wildfires in the southwestern United States and create a different pattern of hurricanes, cyclones and monsoons in the Pacific and Atlantic oceans, as well as cause other regional changes. such as pressure standards in Europe. La Niña typically suppresses hurricane activity in the central and eastern Pacific basins due to stronger vertical wind shear and enhances it in the Atlantic basin due to weaker vertical wind shear and trade winds. However, the Atlantic hurricane season has been quiet so far this year. Despite the recent uptick in activity, with two named hurricanes, Danielle & Earl, the 2022 season continues to lag and the average number of named storms for the season so far. As of today, just six named storms have formed, two of which have become hurricanes and since last night Tropical Storm Fiona – which could become a hurricane next week. That’s about four storms and two hurricanes behind the average pace, according to the National Hurricane Center. However, La Niña has been ongoing since September 2020, and the 2021 Atlantic hurricane season was the third most active Atlantic hurricane season on record. Perhaps because a La Niña triple dip is so rare, we may see more unusual and extreme weather patterns and events that are not typical of more regular La Niña patterns. But even these extreme events of prolonged floods, droughts and heat are amplified by global warming. Which can make long-term predictions this year more difficult, especially in the winter season – which is usually easier to predict than other times of the year. Certainly weather patterns have been unusually blocked in Europe, leading to extreme heatwaves, including in the UK Perhaps we can expect more unusual weather in the coming months?
