Weather to put on a weird show this winter

WASHINGTON -- Get ready for weather whiplash as powerful climatic forces elbow each other for starring roles in a weird winter show.

See Full Article

The spine-chilling polar vortex is taking center stage in Europe and bringing persistent cold to much of North America - except in Hollywood, where soggy El Nino won't give up the spotlight.

After El Nino delivered a balmy Christmas Eve to the eastern U.S. and shattered national records with a warm, wet and wild December, Minnesota may host one of the coldest NFL playoff games in history this Sunday, with wind chills around -29 C, meteorologists predict.

"The biggest thing is this whiplash," said University of Oklahoma meteorology professor Jason Furtado. "It's going to be a shock for people."

The center of the cold blast starts this weekend in the U.S. in the upper Midwest, and then moves to the Hudson Bay area next week, while in Europe it starts in the east and north and then spreads, Furtado said. Europe may have to get used to temperatures 20 or so degrees below normal.

"Temperature will be dominated by the impact of the polar vortex," said Judah Cohen, seasonal forecast chief for the private Atmospheric and Environmental Research company outside Boston. It will feel similar to 2013 and 2014, he said.

Americans became painfully familiar with the polar vortex during those winters. This time, America's winter temperatures will depend on when the wet and warm El Nino pushes itself back to prominence, Furtado said.

"We have all of these large and unusual events happening all at the same time and I don't think it has ever happened before," said Rutgers University climate scientist Jennifer Francis.

For a winter this dramatic, it may help to consult the program:

THE CAST

The star is El Nino, a veteran of this stage for a few decades now. This natural warming of the central tropical Pacific occurs every two to seven years or so, and changes weather worldwide, especially in the Americas and Asia. It is closely associated with heavy rain in California, and general warming. It has less effect in Europe because that's further away. With its flipside, La Nina, it is known as the El Nino Southern Oscillation, and it lasts about a year.

Playing off against El Nino is the Arctic Oscillation, and its index measures differences in atmospheric pressure between the Arctic and mid-latitudes. When the AO is positive in the winter, polar air stays trapped up north and the weather is relatively mild further south. When the AO is negative, the cold Arctic air escapes and plunges into lower latitudes, treating the United States and Europe to the polar vortex - a swirling air mass that carries spine-chilling temperatures.

The North Atlantic Oscillation is a bit player with a big influence over Europe's weather. As with its Arctic cousin, the more negative its index, the colder the continent becomes.

The jet streams also are important to watch. These rivers of air heavily influence local weather everywhere, carrying storms and clearing skies around the planet. Usually in the winter, the jet stream that affects most people in the United States and Europe moves relatively straight from west to east. But when it weakens, it can plunge south and north and even get stuck at times, creating odd extremes.

Another air pattern playing a small but key role is the Madden-Julian Oscillation, which travels in the warm parts of the Indian and Pacific oceans, and may have triggered changes that "flipped the switch" in December, Furtado said.

Still other characters may be a factor in making the jet streams oscillate more wildly: A huge blob of warm water in the northern Pacific, unusually low sea ice levels in the Arctic's Barents Kara sea area; a cool patch of water off Greenland, likely from melting ice sheets and glaciers; winter storm Frank that hit England; and of course man-made climate change.

ACT ONE

This was last month. El Nino appeared in classic form, tying 1997-1998 for the strongest on record. The Arctic Oscillation was very positive, trapping cold air in northern latitudes. With so many warm, wet days further south, spring flowers popped up and trees bloomed in December.

"It's not surprising we were 70 degrees (21 Celsius) on Christmas Day," said Mike Halpert of the National Oceanic and Atmospheric Administration's Climate Prediction Center in College Park, Maryland.

El Nino often spawns winter tornadoes in the southern U.S. and they appeared on cue, killing two dozen people in just four days. The heavy rain that flooded the Mississippi River Valley isn't usually an El Nino signature though, Cohen said.

ACT TWO

The switch flipped: The Arctic Oscillation and its North Atlantic sidekick went negative big time.

"When it's a negative AO, that's when people start mentioning the words 'polar vortex'," Halpert said.

This time, there's cold air, but it's mostly dry so far, despite El Nino, which still spawns a series of rainstorms hitting California. Meteorologists say wetter weather could bring heavy snowstorms, but that's not likely for another week or more, although cities along the Great Lakes may get lake effect snow.

So far the east-moving moisture from El Nino is staying south of the Arctic plunge, but that may change.

For now, the AO is dominating in its fight with El Nino, especially in Europe, Cohen said. NFL players and fans will likely brave temperatures around one below zero in Minneapolis.

ACT THREE

No spoilers here. Will the polar vortex hold the stage for weeks or months? Will the cold AO and wet El Nino combine for whopper snowstorms?

Rutgers' Francis doesn't think the moisture and the cold can keep avoiding each other, saying "we're going to have major major dumps of snow. We just don't know where."

Furtado predicts El Nino will push aside the cold in America, but not in Europe, where it has less of an influence. Cohen is less certain about what will happen as these forces morph and interact over time.

"There's a lot going on; the weather has been crazy," Cohen said. "Expect the unexpected."



Advertisements

Latest Tech & Science News

  • Facebook under heavy criticism from early proponents

    Tech & Science CTV News
    NEW YORK -- Some of Facebook's former friends are starting to express some serious doubts about the social network they helped create. Facebook exploits a "vulnerability in human psychology" to addict its users, Sean Parker, the company's first president, said in a public forum last month. Source
  • Some forests aren't growing back after wildfires, research finds

    Tech & Science CBC News
    Bigger, hotter wildfires are ravaging forests and burning them to the ground more frequently as the climate gets hotter and drier. Now a new study shows that in some places in the U.S., those forests may never grow back. Source
  • Astronomers to eavesdrop on interstellar asteroid for possible signs of intelligent life

    Tech & Science CBC News
    Is anybody out there? That's the ancient question astronomers hope to answer by listening to a newly discovered asteroid that's paying us a visit from beyond our solar system. Scientists from Breakthrough Listen, an international program dedicated to searching for signals that may come from intelligent life beyond our own, want to listen in on the peculiar asteroid, named 'Oumuamua, to see whether any signals are coming from it. Source
  • 'Monster bird' fossil found in New Zealand

    Tech & Science CTV News
    The fossilised bones of an ancient penguin the size of a pro-wrestler have been discovered in New Zealand, scientists said Tuesday, dubbing the creature "monster bird." With an average height of 1.7 metres (5.5 feet) and a weight of 100 kilogrammes (220 pounds), the giant bird is thought to be one of the world's biggest extinct penguin species, easily dwarfing its cuddly-looking modern descendants. Source
  • North American birders flock to N.B. tree after rare bird from Europe spotted

    Tech & Science CTV News
    MIRAMICHI, N.B. -- New Brunswick has a rare visitor from Europe and it's attracting bird lovers from across Canada and the United States. A European mistle thrush arrived in Miramichi on Saturday, and decided to stay. Source
  • Birth of new island could help search for life on Mars: NASA

    Tech & Science CTV News
    NASA researchers are studying the formation of a new Pacific Ocean island in order to find clues for where to search for past life on Mars. Located in the South Pacific nation of Tonga, Hunga Tonga-Hunga Ha'apai began forming after the eruption of an underwater volcano in Dec. Source
  • Fetid attraction: London fatberg to go on museum display

    Tech & Science CTV News
    LONDON -- Part of a monster fatberg that clogged one of London's sewers is destined for fame in a museum. The Museum of London says it will put the only remaining chunk of the 130-metric-ton (143-U.S. Source
  • Telescope to scan mysterious cigar-shaped asteroid for signs of alien technology

    Tech & Science CTV News
    If E.T. has a cellphone, astronomers are hoping to find it. Researchers will use a listening telescope to search for signs of alien technology on ‘Oumuamua, the mysterious, fast-moving, cigar-shaped interstellar object currently speeding through our solar system. Source
  • Pregnant woman wants seat on Tokyo metro: there's an app for that

    Tech & Science CTV News
    Pregnant women struggling to bag a seat on the famously packed Tokyo subway could find their salvation in a new app connecting them with nearby passengers willing to give up their coveted perch. The digital match-making app being trialled this week on the metro aims to overcome two problems especially prevalent in Japan: passengers generally have their nose buried in their phones and talking is strictly frowned upon. Source
  • SpaceX delivery via recycled rocket delayed a day

    Tech & Science CTV News
    CAPE CANAVERAL, Fla. - SpaceX has delayed its latest grocery run for the International Space Station for at least a day. The company now aims to launch its first recycled rocket for NASA on Wednesday. Source