[Image from National Park Service]
[NOAA] For those of you dreaming of a white Christmas, you can find places that have the best chance of being a winter wonderland according to weather history. The “Historical Probability of a White Christmas” map shows the climatological probability of at least 1 inch of snow being on the ground on December 25 in the contiguous United States. On the map, dark gray shows places where the probability is less than 10 percent, while white shows probabilities greater than 90 percent.
Where does history say you should be in the Lower 48 for the best chance of seeing a white Christmas? Most of Idaho, Minnesota, Maine, Upstate New York, the Allegheny Mountains of Pennsylvania and West Virginia, and, of course, the Rockies and the Sierra Nevada Mountains all have a high probability of seeing a white Christmas. And, Aspen, Colorado, is just one of about a dozen locations boasting a 100% historical probability of seeing a white Christmas.
[Table from AMS]
Snowy Climates Based on Data
This map is based on the 1981–2010 Climate Normals, which are the latest three-decade averages of several climatological measurements. This dataset contains daily and monthly Normals of temperature, precipitation, snowfall, heating and cooling degree days, frost/freeze dates, and growing degree days calculated from observations at approximately 9,800 stations operated by NOAA’s National Weather Service. You can find the Climate Normals for locations near you by using NOAA NCEI’s interactive map or search tool.
While the map shows the climatological probability of snow-covered ground on December 25, the actual conditions this year may vary widely from these probabilities because the weather patterns present will determine if there is snow on the ground or if snow will fall on Christmas Day. These probabilities are useful as a guide only to show where snow on the ground is more likely.
Tracking U.S. Snowfall
If you would like to keep track of the snowfall across the United States on a daily basis, see the National Operational Hydrologic Remote Sensing Center’s National Snow Analyses.
[Current snow depth as of 12/4/18]
For a more detailed assessment of the probability of a white Christmas as well as documentation of the methodology used to calculate the map’s underlying climatological statistics, see our scientists’ paper, White Christmas? An Application of NOAA’s 1981-2010 Daily Normals, published in the Bulletin of the American Meteorological Society.
[Table from AMS]
Edited for WeatherNation by Meteorologist Mace Michaels
UPDATE: A Severe Thunderstorm Watch has been extended into eastern Texas until 10 pm CDT. https://t.co/k00SRPmzLD59 minutes ago by WeatherNation
Thunderstorms have been rumbling across Texas on Wednesday. Check out this shelf cloud roll across the sky in Granb… https://t.co/gWNAaBvZTH1 hour ago by WeatherNation