America’s winter wonderland is kicking off this season like anything other than tradition.
The calendar says December but for much of the country temperatures beckon the sandals. Umbrellas, if not crates, are needed in the Pacific Northwest, while in the Rockies snow shovels are collecting cobwebs.
Meteorologists attribute the latest record of extreme weather to a stranded jet stream and the influence of a La Nina weather pattern from the cold waters of the equatorial Pacific.
Astronomically, it is still autumn, but winter begins on December 1 for meteorologists. This year, no one told the weather like that.
On Thursday, 65 weather stations across the country set record highs for December 2, including Springfield, Missouri, which hit 75 degrees Fahrenheit (24 degrees Celsius) and Roanoke, Virginia 72 degrees Fahrenheit (22 degrees Fahrenheit) poison). Cheyenne, Wyoming and Billings, Montana, broke the long-term heat record by 6 degrees.
Areas of Canada and Montana saw the highest December record in recorded history. On Friday, parts of South Carolina and Georgia hit record highs.
In Washington state, Seattle, Bellingham and Quillayute all set records for autumn rainfall in 90 days. Bellingham was watered by a rain of nearly 60 centimeters. The Olympic and Cascade mountains were hit harder, with more than 50 inches (127 centimeters) over three months, according to the National Weather Service. Forks, Washington, receives more rain in 90 days than Las Vegas in 13 years.
On top of that, there is a blizzard warning over the tops of Hawaii’s Big Island with up to 12 inches (30.5 cm) of snow expected and gusts of more than 100 mph (161 km/h).
Meanwhile, snow was missing in Colorado. Before this year, the last first measurable snowfall recorded in Denver was on November 21, way back to 1934. Snow is likely to fall Monday night, according to the weather agency. However, without snow since April 22, this is the third longest stretch the city has experienced without snow.
One key factor: The jet stream — the stream of air that moves the weather from west to east on a roller coaster-like path — just got stuck. That means low pressure over part of the stream is bringing rain to the Pacific Northwest, while high pressure hovering over about two-thirds of the country produces warmer, drier weather, Brian Hurley, senior meteorologist at the Weather Service’s Weather Prediction Center in College Park, Maryland.
If the jet stream moved more or flexed the other way, rain and other extreme weather wouldn’t be as concentrated, Hurley said.
This is typical weather patterns with natural La Nina weather fluctuations, he said. The flip side of El Nino, La Nina is the cooling of parts of the central Pacific that changes weather patterns around the globe. La Ninas tends to bring more rain to the Pacific Northwest and make the South drier and warmer.
Meteorologist Jeff Masters, founder of Weather Underground now at Yale Climate Connections, says these extremes are becoming more frequent as the world warms. But scientists haven’t done the research required to attribute these events to human-caused climate change.
In Boulder, Colorado, meteorologist Bob Henson enjoyed a rare December bike ride on Thursday.
Still, “there’s a lot of anxiety about the lack of snow,” he said. “It puts you in a spiritual dilemma. You enjoy warm weather while being aware that it’s not good for the Earth to warm up. “
https://www.winknews.com/2021/12/04/explainer-stuck-jet-stream-la-nina-causing-weird-weather/ Jet flow is blocked, La Nina causes strange weather