Oak Ridge National Laboratory
In 1942, Bing Crosby crooned about a white Christmas, and a dream is just what a snowy December 25 has become in several parts of the United States, according to statistics provided by researchers at Oak Ridge National Laboratory.
Looking at 16 citiesmainly in the northsince 1960, the number of white Christmases per decade declined from 78 during the 1960s to 39 in the 1990s.
People in Chicago, for example, saw the number of white Christmasesdefined as at least one inch (2.5 centimeters) of snow on the grounddrop from seven in the 1960s to two during the 1990s. In New York, the number declined from five in the 1960s to one this past decade, and Detroit had just three white Christmases in the 1990s versus nine in the 1960s.
But in several cities, the number of white Christmases has been fairly constant.
Looking at the 1960s, 70s, 80s and 90s, Tahoe City, California, had eight, seven, eight and nine white Christmases, respectively. Salt Lake City's number of white Christmases per decade were seven, seven, eight and eight. Minneapolis/St. Paul had eight white Christmases in the 1960s, seven in each of the following two decades and eight in the 1990s.
In Tennessee, Memphis, Nashville and Knoxville/Oak Ridge had several white Christmases in the 1960sthree in Memphis, two in Nashville and four in Knoxville/Oak Ridgebut none in the 1980s or 1990s.
As defined for this survey, Atlanta hasn't had a white Christmas since the record-keeping process began in 1896.
Following are metropolitan areas used in the study followed in parentheses by the number of white Christmases for each of the last four decades:
Seattle (2, 0, 0, 0)
Tahoe City, California (8, 7, 8, 9)
Salt Lake City (7, 7, 8, 8)
Denver (4, 4, 7, 2)
Minneapolis/St. Paul (8, 7, 7, 8)
Kansas City, Mo. (4, 0, 6, 2)
Chicago (7, 5, 4, 2)
Detroit (9, 7, 5, 3)
Cincinnati (3, 0, 2, 2)
Boston (8, 5, 5, 2)
New York City (5, 1, 1, 1)
Washington, D.C. (4, 0, 0, 0)
Memphis (3, 0, 0, 0)
Nashville (2, 0, 0, 0)
Knoxville/Oak Ridge (4, 1, 0, 0)
Atlanta (0, 0, 0, 0)
The snowfall analysis was performed by Dale Kaiser, a meteorologist with the Carbon Dioxide Information Analysis Center at the U.S. Department of Energy's Oak Ridge National Laboratory, and Kevin Birdwell, a meteorologist in the lab's Computational Science and Engineering Division.
For many cities, the weather described by the data is actually what was recorded at a suburban station several miles away, Bob Cushman, director of the Carbon Dioxide Information Analysis Center, said. For example, the weather for Washington, D.C., was actually recorded at Glen Dale, Maryland.
Cushman advised against reading too much into the analysis, saying, "After all, we're only looking at one aspect of weather on one specific day each year. Whether there is snow on the ground on December 25 may or may not relate to the larger issue of whether the U.S., or any region in the country, is experiencing an overall warming trend."
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