Despite frigid conditions in the East, U.S. seeing more record warmth this winter

http://mashable.com/2015/02/18/u-s-winter-extreme-cold-record-warmth/

By Andrew Freedman
Feb. 18, 2015

The U.S. is experiencing one of the most unusual winters in years, with a pronounced and enduring bubble of warm, high pressure over the West, and blast after blast of frigid Arctic air and heavy snow in the eastern two-thirds of the country. The warmth is breaking all-time records, while the cold is rivaling some of the coldest weather in more than two decades.

In fact, the Arctic outbreaks outrank 2014's polar vortex cold waves in terms of severity and duration.

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Ski areas are struggling to stay open in California’s Sierra Nevada mountains in the face of a snowpack that has just 22% of its typical snow water equivalent for this time of year.

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Meanwhile, organizers of Alaska’s legendary Iditarod sled-dog race were forced to change the start of its route from Anchorage to Fairbanks due to the lack of snow cover; this is only the second time in its 43-year history that such a route change has taken place.

In states east of the Rocky Mountains, though, the winter has been unrelentingly frigid and snowy, especially since January.

The Great Lakes, which set records for their ice cover last winter, are outpacing the freeze-up from a year ago. For example, nearly all of Lake Erie has frozen over, with parts of Niagara Falls becoming entombed in ice, though water is still flowing underneath.

Boston has received a whopping 8 feet of snow since mid-January alone, and is on pace to meet or beat its all-time record season of 1995 to 96. Boston’s blizzard blitz is unprecedented in its history of record-keeping, which dates back to the late 19th century.

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However, even with an unusually cold air mass and widespread snow cover, not many all-time cold temperature records are expected to be set. Instead, mostly daily and possibly monthly records are expected to be eclipsed.

It’s getting more difficult to break all-time cold-temperature records, in addition to monthly records, as the overall climate of the U.S. — along with the globe — warms in response to natural climate variability and increasing concentrations of greenhouse gases in the air.

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Although residents of the Midwest, South, and East Coast are justified in complaining about the seemingly never-ending cold and snow, so far this winter, the warmth in the West is outpacing the cold when it comes to record temperatures and overall endurance of the unusual temperatures.

According to data from the National Climatic Data Center (NCDC) in Asheville, North Carolina, there were 3,829 daily high temperature records set or tied in the U.S. during the past 30 days, as well as 3,368 record warm overnight low temperature records set or tied. This compares to just 498 records set or tied for the coldest high temperature, along with 386 daily records set or tied for the coldest low temperature.

A similar disparity is also visible in the monthly temperature records categories, with 278 monthly record highs set or tied, and no monthly records for the coldest high temperature.

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Seven Western states — California, Idaho, Nevada, Oregon, Utah, Washington and Wyoming — had a top-10 warmest month of January this year. What's more, the warmth has been accompanied by dry conditions, as well as relatively warm storm systems that have dumped snow only on the highest mountain peaks.

In San Francisco, no rain fell at the downtown observation station or the airport in January, the first time this happened since records began there in 1850. January is typically that city’s wettest month of the year, and the lack of rainfall has only heightened drought concerns.

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Arndt noted that neither the polar vortex cold waves of 2014, nor the Arctic outbreaks this year so far, have been breaking temperature records set in the extremely cold winters that occurred in the 1970s and 1980s. Instead, they’ve been eclipsing records from the past 10 to 20 years.