It develops over tropical or subtropical waters, and has an organized circulation. The study is published in Geophysical Research Letters.The official Atlantic Basin Hurricane Season runs from June 1st to November 30th.Ī tropical cyclone is a warm-core, low pressure system without any “front” attached. “One of the reasons for our successes so far is we are proactively tuning and revising our model every year,” Zeng says. This is the ninth consecutive year of the University of Arizona researchers’ hurricane forecasting. In June, the forecasters use a combination of the output from the forecasting model and observational data from March through May. Using machine learning, Zeng’s research group processes the forecast released by the European organization. In April, their forecasting is based on the seasonal prediction from the European Center for Medium-Range Weather Forecasts, an independent intergovernmental organization that produces global numerical weather predictions. But for predicting hurricane seasons ahead of time, the initial condition of the wind does not matter much.Įach year, the researchers release their hurricane predictions initially in April and again later in June. So, for individual hurricanes, the initial wind condition is crucial. “The wind today will change tomorrow or two weeks later, unlike ocean temperature that stays the same for a long time.” That’s because “atmospheric winds do not have long memory,” Zeng says. Though atmospheric wind is a great metric for predicting individual hurricanes, as noted in a recent study published by Zeng and his collaborators, wind measurements are not useful for predicting hurricane seasons. In the clouds, water vapor condenses and forms droplets that further fuel the storm by releasing heat.Īccording to the National Oceanic and Atmospheric Administration, the federal agency for weather forecasting, wind speeds that reach 74 mph within a storm are classified as hurricanes. The warm ocean air rises and cools, leading to the formation of clouds and thunderstorms. They begin as low-pressure areas and subsequently enhance thunderstorm activity as they move through the moisture-rich tropics. Hurricanes are violent storms that form over warm tropical oceans. The forecasting team is not yet certain which ocean basin will be the “winner” in the battle and will update its predictions in June. This year, due to the activity of El Niño, or the warm phase, less hurricane activity would be expected over the North Atlantic.īut at the same time, the ocean surface temperature over the Atlantic this year will also be very warm, and that tends to increase hurricane activities, Zeng adds. While El Niño represents an above-average temperature of the sea surface over the eastern Pacific, La Niña refers to the periodic cooling of sea surface temperature. “We expect a good, nice El Niño to come back after a few years of La Niña,” Zeng explains.Įl Niño and La Niña are two opposite extremes of sea surface temperatures, rainfall, surface pressure, and atmospheric circulation happening across the equatorial Pacific Ocean. This year is particularly interesting, Zeng says, because there will be a fight between two big ocean basins over which will have greater influence on hurricane activities, thanks to the rising eastern Pacific Ocean sea surface temperature compared to previous years. The good news this year, is that fewer hurricane landfalls are expected compared to 2017. In 2017, there were 10 hurricanes, six of which were very damaging, Zeng says. Historically, the average number of hurricanes per year has been seven. The researchers are forecasting nine hurricanes this year, five of which are expected to be major hurricanes. That’s our message,” says Zeng, adding that the East Coast and Gulf Coast are typically the regions where hurricanes have the greatest impacts. “This will be a very active hurricane season. That said, he emphasizes that “people should get prepared.” “We are not expecting this to be as damaging as 2017,” Zeng says. Since 2014, hurricane activity has been accurately predicted by a model created by Xubin Zeng, a professor of hydrology and atmospheric sciences at the University of Arizona, and his former graduate student Kyle Davis. The forecasters expect the number of major hurricanes this year to be similar to 2017, which saw the extremely intense hurricanes Harvey, Irma, and Maria. After two years of relatively mild hurricane seasons, 2023 will see above-average hurricane activity, researchers predict.
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