You know, we’ve been down this road before. There was a small chance of snow on Christmas in 2007. (Here is a sample blog post from Christmas Eve.) We had a little freezing drizzle on Christmas Eve in 1998. In 1985, there was a dusting on Christmas Eve where I lived in Center Point, and the BHM airport reported a trace of snow. 5 inches of snow fell in BHM on December 22, 1929, but it was 51 degrees on Christmas Day. However, to my knowledge (Bill Murray can answer this better than I can), snow has never been on the ground in Birmingham on Christmas morning is recorded history.
The chance of snow on Christmas this year, even though it is still 8 days away and impossible to accurately forecast, is creating quite a buzz. Like James has been saying, no one knows for sure if, where, or how much it will snow on Christmas this year, and if anyone who tells you they know for sure, make them promise to cut your grass for a year if it doesn’t and see if they don’t hesitate.
Here is the early story on this. The models are indicating a low pressure area will develop somewhere over the SE US next Wednesday, bringing precipitation to the region. Right now, it looks like that surface low will be too far north for a significant snow here, instead bringing it to Tennessee, North Carolina, or Kentucky. But, it is possible that could change. Also, as shown in the loop from the GFS model below, 3 of the 4 major models that go out to 8 days (the GFS, European, and Canadian), indicate that the upper level low will “cut-off”, as sometimes occurs with rapidly developing storms when the dynamic cooling associated with the system cools upper-level temperatures NW of the surface low.
If that happens, the upper-level low could make it unstable enough, and create enough lift, for some light snow on the back side of the system Thursday night and Friday (just in time for Christmas). However, there would have to be enough moisture, and the lift of the low would have to not be offset by the sinking produced by cold air moving in at the same time.
This will be very fun to watch for us weather people and for everyone. We’ll have frequent posts on the blog, and we should have a better idea by Monday, when Christmas is in the time range of the short-term models. Chance of White Christmas (snow on ground on Christmas morning in Birmingham): 10%.
