Tufts by Numbers: Snow day calculations exposed!

Monday afternoon, I sat in the Mayer Campus Center refreshing snowdaycalculator.com, looking up “school closings Boston area,” my fingers crossed tightly, hoping that this wacky March temperature would grant us our second full snow day of the semester. I wondered what kind of calculations went into judging whether school would be closed for a storm and what statistics exist nationwide about snow day closings.

In 2014, Reddit user Alexandr Trubetskoy recorded the different snowfall amounts across the country that merited a snow day on an informational map. According to the data that he collected, here in Massachusetts, an average of 12 inches of snowfall can merit a snow day. Yet, in southern states such as North Carolina and Tennessee, any small amount of snow can cause a school closing.

My own snow day hopes came true when eight-to-12 inches of snow was expected to accumulate in Medford on Tuesday. This merited a snow day not just for Tufts but for all high school and college students in the area. On our previous snow day this semester on Feb. 9, the snowfall amount was approximately 10 inches. In contrast, the delayed opening on Feb. 13 came with just two inches of snow during the day. These amounts align with Trubetskoy’s data on snowfall and school closings, falling comfortably near the 12-inch number that Trubetskoy determined was the amount of snowfall that merits a school closing here.

When refreshing snowdaycalculator.com, this locational data is factored into the probability calculation along with weather updates issued by weather.gov. The calculator also provides opportunities for users to enter other relevant information, such as the number of snow days that their school has had in the current year and whether their school is public, private, urban or rural. The calculator’s creator, MIT graduate student David Sukhin, doesn’t reveal the algorithm that he uses for the calculator. But its success has served students across the country who rely on the calculator to determine whether to prepare for classes the next day or not. The calculator has garnered use nationwide and can receive up to 250,000 hits during a severe storm, according to a Feb. 12, 2016 CBS Boston interview with Sukhin.

The frequent use of snowdaycalculator.com by Tufts students points to the trust that many have in the site. In a Feb. 20, 2016 interview with WCVB Boston, Sukhin noted that since the calculator’s conception in 2012, it has only been wrong about Boston-area predictions once or twice. He also echoed that the trends outlined by Trubetskoy’s map ring true in the calculator’s predictions -- Boston-area schools are more likely to have a snow day than those in upstate New York and Michigan with the same amount of snowfall but less likely than those in states south of us.

Here at Tufts, unpredictable East Coast storms can often cause an emotional roller coaster ride as we determine whether to prepare for a snow day or not. The snow day calculator and trend history of snowfall’s correlation with school closings can help us predict snow days on our own campus, and -- perhaps more importantly -- decide how many more hours we can stay curled up in bed, avoiding the stormy outdoors.