Since many of you asked for me to do this, I decided to make a White Christmas probability map. Now, probability maps can be hard to interpret, so let me briefly explain everything a bit further. Climatologically, most Christmas snows are confined to the northern U.S. and the mountains out west. Because of the coming pattern flip that will significantly increase the United States snow chances (even unusually far to the south), I am going against climatology and am much more bullish on widespread snow cover across the U.S. this Christmas or right around that timeframe.
For those of you that follow my forecasts closely, I typically try to identify any pattern change or potential storm development several weeks out, and then I fine-tune those forecasts as we get closer to the event. We’re still over 10 days away from Christmas, and while I am confident that a winter storm will occur right around Christmas, it’s very difficult to determine if it will actually happen on Christmas Day, or where it’ll track.
Right now, snow cover extent across the United States is very low, but that will begin to change as we get around Christmas and beyond. Putting together this probability map was particularly tricky because Christmas will be the timeframe that the pattern will actually be flipping back colder, similar to what we had in November except colder. As any meteorologist knows, saying that a storm is going to happen on an exact day is difficult beyond five to seven days, but identifying a pattern change beyond seven days can be done and can give some strong hints as to what should be expected later down the road.
Because I am expecting a winter storm right around Christmas and a potential pre-Christmas storm next weekend, you will notice that I have most of the U.S. with a chance at having a white Christmas. What may even be more surprising is that I have a 15 to 30% chance of a white Christmas across a large region of the southern U.S., which is unheard of for this time of year. The reason I did this was because of the potential storm around Christmas, but if for some reason I see that this storm will occur right after Christmas (say the 26th or 27th), then I will cut back those chances in my future probability map that I’ll be putting out next Sunday. Typically, the southernmost regions in the 15 to 30% zone have less than a 5% chance of seeing a white Christmas.
If you missed my detailed article yesterday explaining all of my predictions for this timeframe, please click here. Below, I decided to post the historical chances of a white Christmas, so as you can clearly see, I’m definitely going against climatology this year if you compare it to my map above.
I will continue to keep you updated on the winter storm potential around Christmas. Please like and follow Firsthand Weather on Facebook and Twitter.
Matthew Holliday is a graduate of the University of Oklahoma, where he completed a B.S. in Meteorology and a B.S. in Geographic Information Science. Matthew founded Firsthand Weather in 2010 as a senior in high school and maintained the site through his undergraduate career. Research that was conducted by Matthew while at OU involved determining the synoptic environment in which various types of wave clouds (including vertically propagating waves and trapped waves) develop in Boulder, Colorado and Norman, OK. Matthew also did research on spatial changes in tornado activity across the United States . The goal of this study was to determine if spatial changes in tornado activity had occurred and if those changes could be linked to changes in average surface dew point temperature. Matthew has completed coursework in dynamics, thermodynamics, cloud physics, calculus and differential equations, statistics, remote sensing, GIS, synoptic meteorology, and mesoscale meteorology. His goal is to provide his audience with a deeper understanding of what drives our weather and climate, while making it easy and enjoyable to learn.