The coming U.S. winter is likely to be somewhat low on snow and extreme cold outbreaks, with federal forecasters predicting the North will be warmer than normal and the South wetter and stormier.
A strong El Niño moderates and greatly changes the storm tracks the United States will likely face from December to February, with additional warming due to climate change and record-breaking ocean temperatures, National Oceanic Administration officials said Thursday. and Atmospheric when publishing its report on winter. panorama.
The forecast warmth will likely turn some storms that would have dumped snow into rain in the northern part of the country, but there is also “some hope for snow lovers,” with one or two possible nor’easters on the East Coast, Jon said Gottschalk. chief of the operations branch of the NOAA Climate Prediction Center.
Parts of the East Coast, particularly the mid-Atlantic, may get more snow than normal because of this, he said.
Most of the country is forecast to be warmer than normal, with that heat spreading northward from Tennessee, Missouri, Nebraska and Nevada, along with nearly all of California. The rest of the country is forecast to be near normal or have an equal chance of having warm, cold, or normal temperatures.
NOAA does not predict that any part of the US will be colder than normal this winter.
El Niño and climate change are forecast to turn potential snow storms into rain.Getty Images
“The greatest chances for warmer-than-average conditions are in Alaska, the Pacific Northwest and northern New England,” Gottschalk said.
A similar swath of the country’s south is expected to be wetter. The additional moisture forecast extends from Massachusetts to the East Coast along most of the South below Tennessee and extends westward across Texas, Kansas, Colorado, Utah, Nevada and most of California, but excluding good areas of New Mexico and Arizona.
The Great Lakes region and the northernmost parts of the country, stretching from Lake Erie to eastern Washington, are forecast to be drier than normal.
This is all due to El Niño, which is a natural periodic warming of parts of the Pacific that changes weather patterns around the world and generally raises global temperatures, Gottschalk and other NOAA scientists said. El Niño has its strongest effects, especially in the United States, during the winter. That’s when it sends the jet stream, which moves storm fronts, down an unusual path dominated by warmer, moister Pacific air rushing south.
That means more rain in the south and more storms in late winter, Gottschalk said. El Niño often means “unusually severe weather across the state of Florida due to a strong subtropical jet stream,” he said.
Those changes in the jet stream can often cause a storm along the East Coast with moisture from the Caribbean and Gulf of Mexico to “intensify a lot” and fall as heavy snow in large eastern cities, he said. Gottschalk.
That depends on the timing of temperatures and other conditions, so it’s not likely to happen more than a couple of times. But if the timing is right, “these storms can really explode off the East Coast,” he said.
He pointed to the crippling 2010 Snowmageddon storm in Washington, which dumped more than 2 feet on the capital region during an El Niño event.
Normally, the South not only becomes wetter but also colder during El Niño, but Gottschalk said warmer ocean temperatures and record summer temperatures led forecasters to rule out a colder outlook.
NOAA scientists said climate change is an additional factor in their forecast, especially because winter is a season when the world experiences some of the highest warming than former normals due to the burning of coal, oil and natural gas. Winter in the lower 48 states has warmed an average of 1.6 degrees Fahrenheit (0.9 degrees Celsius) over the past 40 years, according to NOAA data.
Meteorologists outside NOAA see winter developing somewhat similarly.
Washington, DC, was buried under more than 2 feet of snow during El Niño in 2010. Getty Images
Judah Cohen, a winter storm expert at Atmospheric Environmental Research, a commercial firm outside Boston, has become prominent due to his successful forecasts based on the fall’s Siberian snowpack and study of the infamous polar vortex. The Siberian snowpack, El Niño and other factors “indicate a mild winter overall,” he told the Associated Press.
When there is less snow in Siberia, the polar vortex, a mass of cold air centered at the top of the globe, tends to stay strong and keep frigid Arctic air locked in near the pole, Cohen said. When there is more snow, the polar vortex is weaker and frozen air escapes toward the United States.
People on the East Coast should be prepared for “climate whiplash” with little snow overall except for one or two real blockbusters, especially in the mid-Atlantic, Cohen said.
Private firm AccuWeather forecasts below-average snowfall in Boston, New York, Pittsburgh, Buffalo, Chicago and Minneapolis, near-average in Kansas City, Salt Lake City and Philadelphia and above-normal in Denver.
AccuWeather predicts less heat than NOAA, with parts of Southern California, New Mexico, Arizona, Texas, Oklahoma, Arkansas, Mississippi, Alabama and Tennessee colder than normal.
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Source: vtt.edu.vn