So much for the "polar vortex." Even with the cold air outbreaks in the Midwest and East during January, the month wound up being just 0.1 degree Fahrenheit below the 20th century average in the lower 48 states, the National Oceanic and Atmospheric Administration (NOAA) said on Thursday in its January climate report. Unusually mild and dry conditions in the West helped balance out the cold in the East, NOAA said.
Notably, although January was the coldest such month since 2011, not a single state had its coldest January on record.
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The month featured a split screen nation, with almost everywhere east of the Rockies experiencing colder-than-average conditions, and areas west of the Rockies experiencing unusually warm conditions. For example, while Michigan and Georgia had a top 10 coldest January, Arizona, California, and Nevada had a top 10 warmest January.
The divide between East and West during January was the result of a buckle in the jet stream that rerouted Pacific storms north, into Canada, bypassing drought-ridden California, before opening the door to the Arctic refrigerator by steering upper level winds from north to south across the East.
The weather pattern across North America resulted in a rare feat, with Anchorage, Alaska, winding up warmer than New York and Philadelphia.
The U.S. was divided into two nations during January, with a cool East and a warm West.
Image: NOAA.
In terms of record temperatures set or tied during January, cold records handily beat warm records, with more than two and a half as many record cold daily highs and lows compared to warm daily highs and warm daily lows.
Over the long-term, though, the U.S. has seen an increasingly lopsided records ratio, with far more warm temperature records set or tied compared to cold temperature records, a trend that cannot be explained by natural climate variability alone, pointing to manmade global warming as a key suspect.
January was also marked by dry conditions, especially in the West. California had its third-driest January on record since 1895, and both the 12 and 24-month periods ending in January 2014 were the driest on record, according to Victor Murphy, a meteorologist at the National Weather Service. The dry December and January have sent California officials scrambling to figure out how to manage dwindling water supplies, since the state relies heavily on mountain snowpack for water during the dry season. December and January are typically the state’s two wettest months, but this year only 0.94 inches of rain fell across the state on average, which was more than 7 inches below normal, NOAA said.
“As of Feb. 1, most mountain locations in California had less than 50% of normal snowpack and reservoirs across northern and central regions of the state had storage levels between 37% and 75% of historical averages for the date,” NOAA said.
The Alaska warmth was especially rare, since it was the warmest January in the Frontier State since 1985. At Lake Clark National Park, the temperature reached a high of 62 degrees Fahrenheit on Jan. 27, which tied the record for the warmest temperature ever observed in Alaska during the month of January.
Monthly average temperature departures from average during January in northwest Canada and Alaska.
Image: NOAA.
The U.S. climate data, released by NOAA’s National Climatic Data Center in Asheville, N.C., precedes a report on global temperatures that will be released next week. That report is expected to show that January continued the nearly 29-year streak of above average global surface temperatures.
Of course, the global data, and the knowledge that Alaska was milder than much of the Midwest and East, does not provide much consolation to those who endured a month of teeth-chattering cold.
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