Jan 2, 2015 10:50 PM
Clayton Stiver Explains More About Snow Squalls
NH1 Chief Meteorologist - NH1.com
On Friday Morning, areas across NH saw scattered snow showers and snow squalls. A cold front that tracked across the area helped add energy to the atmosphere to get the snow going. A westerly breeze hitting the mountains also helped create the snow showers and snow squalls. When wind hits the mountains, air is forced upwards. The rising air cools and condenses and eventually precipitation forms. When we see snow that forms from winds hitting the mountains, we often refer to that as upslope snow in meteorology.
Sometimes, these scattered snow showers can be very intense in small areas. A heavy amount of snow can fall in a short amount of time leading to whiteout conditions. Winds pick up and visibility is rapidly reduced creating treacherous travel conditions. This was certainly the case with the multi-car pile up on I-93 Friday Morning. This is what we refer to as a snow squall. We can sometimes tell when snow squalls may occur, but it's very hard to predict where exactly they will set up and just how intense they will be. It's very similar to a t-storm prediction. We can often tell when the atmosphere will be prime for t-storm development, and maybe even severe storm development, but being able to know where exactly t-storms will form and just how intense they will be is quite challenging.
Also, similar to t-storms, with snow squalls, you can go a short distance away and there will be absolutely nothing...the sun may even be out.