Meteorologists all over the country are geeking out over this storm. It will be one of those storms that is talked about for years. No so much for us down here in the south, but certainly for those states bracing for 20' of snow. I figured in today's weather blog we'd talk about the dynamics of how something like this can form.
Let me start by sharing a link with you. This was written by Meteorologist Austin Gibbons, a colleague that I went to school with at The University of Michigan. He currently lives in Chicago and is going to be smack dab in the middle of some of the day's worst weather. If you are a weather nerd, I highly encourage you to read this: http://apgweather.wordpress.com/
Down here, all we have to worry about is the passing of some nasty thunderstorms. That should happen about 3PM Tuesday afternoon. The question we have to worry about most is: are there going to be tornadoes? As of now, there is a small chance for them and you know we'll be watching it throughout the day.
The bigger story, and of course you know this if you've watched ANY news the last few days, is the MONSTER snowstorm that is bearing down on the Midwest and Northeast. 20' are expected for areas surrounding Chicago, between 12-16' for Detroit and equal amounts for areas on the east Coast. After the storm passes, I'll post the snowfall totals, for now however, let's talk about how it all forms.
For the last few days the Gulf has been soaking the atmosphere with moisture. Winds have been out of the south/southeast for roughly 3 days and the atmosphere is very saturated and warm for areas east of the Great Plains. Since Monday, very cold, very dry air has been digging south from Canada. The collision of these two air masses is causing what we call frontogenesis. Frontogenesis is the forming of, or strengthening of, a frontal system. In this case, it's a cold front. The frontal line is an area of strong instability where the moisture will rise, condense into clouds and then start dropping precipitation.
Picture it like this: the atmosphere is a water balloon and the moisture from the gulf is making the balloon bigger and bigger. The front is the pin that pops the balloon, thus releasing all the water. Well the water balloon here is pretty big at this point... and since the atmosphere is cold enough all that water is going to fall as snow, And that's a lot of snow.
I'd love to keep talking about this system (and Lord know, I probably could) but things are starting to get pretty busy in the Weather Center right now. Follow us on Twitter for constant updates throughout the day.