PENNSYLVANIA — A significant snowfall of up to a foot from a single weather system in March is uncommon in Pennsylvania, but historical weather data shows that it is certainly possible.
March is considered a transitional month between winter and spring across Pennsylvania, according to the National Weather Service.
Average temperatures begin to rise, but the atmosphere can still support strong winter storms when the right combination of cold air and moisture is present. Meteorologists note that large late season snowstorms have occurred in the state several times over the decades.
One notable example occurred during the March 1993 “Superstorm,” which brought widespread snowfall totals of more than a foot to parts of Pennsylvania. Other major March storms have also produced double digit snowfall totals, including events in March 2017 and March 2018 when several Nor’easter systems tracked along the East Coast. Those storms delivered heavy, wet snow across portions of the state, particularly in central and eastern Pennsylvania.
Climatological data shows that Pennsylvania’s mountainous terrain and proximity to moisture from the Atlantic Ocean can help intensify certain storm systems. When a coastal low pressure system develops and pulls cold air into the region, snowfall rates can increase rapidly, sometimes producing several inches per hour.
Snowfall of a foot or more in March typically occurs when cold air remains firmly in place while a strong low pressure system moves through the region. Even though average daytime temperatures may be higher than in midwinter, nighttime temperatures and atmospheric conditions can still support heavy snow accumulation.
While such events are not typical for March, past weather records demonstrate that Pennsylvania can still experience significant winter storms late in the season when the right atmospheric setup develops.
