Thursday, January 17, 2013

Arctic Blast Coming, But It Could Be Worse

By the end of the weekend, you will feel the first taste of the Arctic air that will be charging into the area. Highs are expected to plummet into the lower 20s on Sunday and will be stuck in the teens for highs on Monday and Tuesday. Here is a look at one of the upper level charts I’ve been analyzing. This is the GFS 850mb temperatures. This is showing a surge of cold from Canada with temperatures at this level (~5,000 ft) falling to -22° C on Monday morning.

Will record cold be in the mix? Not even close. We may slip to, or just below zero in a few areas, but one major ingredient is missing. The lack of snow cover is the key – snow cover plays a big role in creating an environment suitable of extreme cold. Without snow, the cold Arctic air mass will “modify” or not be able to sustain its true very cold arctic characteristics. Think of it like this, snow on the ground acts as a “natural ice box” in the environment. Snow cover also reflects incoming sunlight during the day and allows for intense radiative cooling at night. Our snow cover has been noticeably absent. Here are the snowfall statistics for this season so far:

Without snow on the ground and with little, if any chance of that changing the next week, the worst of this cold snap will not be showing up this time around.