The reason for this is the jet stream. Usually, the current moves east in a straight line over Canada or the northern US, but this winter it has swung south, creating areas of high pressure and drought in the west and moving the cold polar air towards the southeast.
Crazy winter in the USA. Several blizzards on the east coast brought negative record highs in the north and the shift of the snow line in the southern states to the Atlantic coast, areas where snow is rare, including Atlanta, Georgia. At the same time, there is a drought on the west coast that has even affected Alaska.
The reason for this is the jet stream. Usually, the current moves east in a straight line over Canada or the northern US, but this winter it has swung south, creating areas of high pressure and drought in the west and moving the cold polar air towards the southeast.
There are three factors that affect the jet stream, one, natural random variation in the weather, the second - a weather configuration in the Western Hemisphere known as the Pacific Decadal Oscillation, a kind of relative of El Niño that warms the North Pacific Ocean and causes the jet stream to be pushed south , and finally a new theory holds that the warming of the Arctic region and the shrinking of the ice sheet in the summer as a result of man-made warming caused a shift in the jet stream patterns, and unpredictable weather.
These crises can also be seen from space. NASA says that the entire western part of the US is changing color due to the strongest drought in over a decade. According to the US Department of Agriculture and the National Oceanic and Atmospheric Administration (NOAA), extreme drought conditions now cover 62% of California's land area, and no relief is in sight.
JPL climate scientist Bill Pechert says to make matters worse, the amount of snow that fell in the Sierra Mountains, which serve as a water reservoir for California, is less than 20% of the normal amount for this time of year.
A NASA video about the drought
NASA's TERRA satellites photographed the bare peaks of the Sierra Nevada mountains, where you see bare rock and mud instead of thousands of square kilometers of white snow.
Passert blames the bastion mainly on the Pacific Decadal Oscillation (PDO), a fluctuation in sea surface temperatures in the Pacific Ocean. Currently the PDO is in negative mode - conditions associated with high pressure levels that block the storms from reaching the West Coast and cause them to stall in the Midwest and East Coast. However, he is still not quick to blame global warming, although he says that ultimately climate change will make the drought worse.
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It should be understood that the climate zones will now have a higher variability than what we are used to in the past.