Many extreme weather phenomena are hitting the United States in mid-March. Forecasters describe a country beset by both torrential rains, a polar cold wave, a heatwave, and strong winds.
Nothing spares the United States. The country, 17 times the size of France, is experiencing a significant number of extreme weather events in mid-March.
The residents of Washington DC experienced a day on Wednesday, March 11th, where the temperature reached around 30°C, double the seasonal norms. The next day, snow appeared in the nation’s capital as shown in this ABC News video, where snowflakes can be seen falling on a cherry blossom tree.
“Throughout the country, even if extreme conditions are not necessarily observed, we will generally see an alternation between cold and hot, or between hot, cold, and hot,” said Marc Chenard from the National Weather Service to AP.
Meteorologist Ryan Maue, who worked for the National Oceanic and Atmospheric Administration (NOAA), stated that he expects extreme weather phenomena in all 50 states.
Temperatures over 40°C in the Southeast
A heat dome, a pocket of warm air stagnating for several days like a bell, will make the Southeast of the United States swelter. Forecasters estimate that the temperature will reach 37°C in Phoenix, Arizona as early as Tuesday, and will continue to climb to 42°C in the following days. AP notes that this city usually records this temperature in May.
Conversely, the polar vortex, a major low-pressure system that forms at about 30km altitude above the North and South Poles, will cause a very significant temperature drop in the Midwest and East of the country, with temperatures dropping below zero. Minneapolis and Chicago, cities accustomed to cold waves, are particularly affected, but the effects of the vortex could also reach the Southwest, like Atlanta in Georgia, as indicated by Ryan Maue to AP.
Snowstorms and strong winds
Over the weekend, two successive low-pressure systems are expected to cause significant snowfall in North America, fueled by the already mentioned polar vortex.
Furthermore, a vast area between Kansas, Oklahoma, and the Gulf of Mexico is expected to experience gusts of nearly 100 km/h this Sunday. Strong winds are also affecting other states further north, like Nebraska, where the local crisis management agency has issued alerts for fire risks.
Hawaii is also being affected by a violent weather phenomenon with the presence of an atmospheric river above the archipelago, bands of warm and humid air carrying large amounts of vapor, leading to very heavy precipitation. Torrential rains are hitting Hawaii, with some rivers on flood alert.
Meteorologists contacted by AP attribute these calamities to the disruption of the “Jet stream.” This 2-3 km thick wind tube thousands of kilometers long that circulates around the hemisphere from west to east has suddenly shifted. “This means that we are observing many extremes one after the other,” Ryan Maue illustrates to AP.
Many studies have established a link between the unusual activity of the Jet stream and the polar vortex and the decline of the Arctic ice cap as well as human-induced climate change, adds the Agency.
