El Niño to blame for unusual Christmas weather. Here's why
Friday, December 25, 2015, 8:00 -
Christmas is around the corner, and many of you who normally get to see snow, fall from the sky or at least on the ground, are in for a big surprise. This year's weather pattern has a clear protagonist, it's called El Niño, and he has a lot to say about whom will and won't get a white Christmas.
A very warm December in the Eastern States
The first half of December has already been different, shattering thousands of temperature records especially across the eastern half of the country.
The warmer than usual weather has been so intense that several cities in the Midwest and Northeast have set daily record highs in the middle of the night or early morning, and some have broken all-time highs for the whole month of December.
While there was some cooling over the weekend for eastern parts of the country, temperatures have rebounded thanks to a dip in the jet stream.
"The jet stream is plunging into the west, allowing cooler air to pool further south...when the jet rises, it forms a ridge keeping the cold air bottled up to the north," explains Weather Network reporter Rachel Schoutsen.
Snow will continue to accumulate in the Pacific Northwest and Rocky Mountain states through Christmas, adding another foot or two in the higher elevations.
Meanwhile, all eyes are on a potential tornado outbreak Tuesday and Wednesday across parts of the south, as warm moisture from the Great Lakes to the central Gulf Coast coincide with ample deep shear in the atmosphere over the next couple of days. Details on that storm will be updated here.
CLICK BELOW TO WATCH: Severe storm risk through Christmas
How El Niño is influencing December weather
A record breaking El Niño has a lot to do with the ridiculously warm weather we are experiencing in many states this month.
Warm sea surface temperatures in both the Pacific and Atlantic, a jet stream located well to the north of it's usual position and very little snow on the ground in the east, are all positive feedbacks to get those temperatures well above normal.
During strong El Niño events, the position of the jet stream further to the north prevents colder Artic air to slide down through Canada into much of the eastern half of the US. Meanwhile, a mild moist west to east flow from the Pacific helps regulate temperatures while bringing heavy rain and snow into much of the Northwest.
The warmer temperatures caused by this El Niño pattern mean less snow on the ground in the east, and more solar energy available to heat the air. Although the sun is at a low angle this time of year, much of the radiation received by the surface get's absorbed rather than reflected back to space by highly reflective snow. This can definitely add a few more degrees to the final temperature.
As of today weather forecasts indicate that this will be a split white Christmas, with better chances of seeing snow from the Sierra Nevada's and Cascades east through the Rocky Mountain states into the upper Midwest and western Great Lakes, and as far south as the Texas, Oklahoma panhandle. However don´t count on seeing much white east of the Mississippi River Valley except for sections of extreme northern New York, Vermont, New Hampshire or Maine.
Is the mild winter here to stay?
So, how long will this warm temperature scenario last? It's hard to pin point down exact dates, but very possibly at least of and on into early next year. Despite the warm start of this winter in many states, weather can usually make some sharp turns. Last year, December was also warmer than average over much of the country and then the winter made a 360 degree turn in the northeast, bringing record snow for parts of New England during the early months 2015.
When asked about the future of these warm US winters, researchers from the Department of Atmospheric and Oceanic Sciences at UCLA suggest that strong El Niño events like the one we are experiencing this 2015-16 could be more frequent in the future bringing climatic chaos to many areas of the world.
The current El Niño should be reaching it's peak about now and begin to tapper off slowly as the winter moves along, however we have yet to see the worse side of the phenomenon in the coming months.
CLICK BELOW TO WATCH: Official US Winter Forecast for 2016
Historical White Christmas hotspots
Historically, Minnesota, Maine, Upstate New York, The Allegheny Mountains of Pennsylvania, West Virginia, Idaho, and the Rockies or the Sierra Nevada Mountains have had the best track record for a White Christmas, according to NOAA.
SEE ALSO: Getting a grip on winter driving
The map below shows the historic probability of there being at least 1-inch of snow on the ground in the Lower 48 states on December 25 based on the latest (1981-2010) U.S. Climate Normals from NOAA's National Climatic Data Center. Dark gray shows places where the probability is less than 10 percent, while white shows probabilities greater than 90 percent.
Click below to watch: It will be warmer in New York than in Los Angeles this Christmas
Be sure to refer back to this article for upcoming details on Christmas weather and travel conditions. Daily updates on your White Christmas forecast can also be seen in the video that leads off this article.