Developing a Climatology of Northeastern Snow Squalls

Snow squalls are some of the most difficult meteorological phenomena to classify, and can be among the most dangerous. With low visibility, strong winds, and winter precipitation occurring within a very narrow time frame‒ from within an hour to as short as 15 minutes, they are a serious hazard, especially on the roads. Since they occur within such a short time frame, it is difficult to inform the general public rapidly enough for there to be a strong awareness of them. Furthermore, due to the fact that these types of storms do not produce high snowfall amounts, they do not always elicit the same attention as more extreme east coast winter storms. To better understand the overall climatology and spatial patterns of these types of weather phenomena, we defined more precisely what a snow squall is using an automated procedure, setting parameters for wind speed, wind direction, and visibility, and utilized hourly ASOS data from stations along the interior of the Northeastern U.S. obtained from Iowa State University’s Iowa Environmental Mesonet (IEM). Weather events prior to that station’s installation of ASOS were removed from the data to avoid inconsistencies arising from human inaccuracies in observations. This allowed us to determine the frequency of snow squall events at those weather stations as well as spatial trends using GIS software. The results of this work presents a new climatology for snow squalls, which puts forward a more comprehensive classification that can help better predict the areas most impacted by snow squalls in the future.