Extreme weather at the 'U'

Wednesday, April 10, 2019 - 12:46am


Visualization by Robert Lesser and Willa Hua

After classes were canceled in January this semester, I wondered just how extreme weather conditions must be in order for an extreme decision like this to be made by the University. Though there is no official record of school closings, The Daily archives show the University has only canceled classes for extreme weather six times for a total span of eight days since it was founded in 1817.

The first time the University closed was during the winter of 1945, and though no specific date could be found, we know it was only for one day. The second closing on Dec. 2, 1974, was caused by extreme snowfall from the previous day. The third happened Jan. 27 and 28, 1978, and it was the first time the University canceled classes for more than one day.

Between 1978 and 2014, the University changed its definition for canceling classes due to weather from “Closure for Weather” to “Reduction of Operations for Weather.” The reason for this change seems to be that the closure of some University facilities, such as dorms and dining halls, would leave students stranded in a time of extreme weather. Therefore, some University operations such as classes and academic buildings would be shut down for extreme weather, but not integral operations relating to students’ safety and well-being on campus like operations providing access to University grounds and communications. This change was first exhibited on Jan. 28, 2014, when the University reduced operations by canceling classes, making this the first cancellation due to weather in 36 years. The University canceled classes again a year later on Feb. 2, 2015 due to extreme cold and heavy snow.

Most recently, on Jan. 30 and 31, 2019, the University reduced operations by canceling classes for two days.

This research, and the cancellations that occurred this semester, prompted me to collect weather data for the four winters where the University canceled class from the National Oceanic and Atmospheric Administration. I wanted to know why these cancellations were so few and far between.

This scatterplot shows the most extreme weather days from 1960 to 2019, and displays where the exact days of school closures have fallen over this time.

In order to contextualize the conditions of each individual winter, I created this graph, which shows temperatures and snow depth for each of the four winters during which the University canceled classes, with the red line indicating when the University canceled classes.

The data shows that the reduced operations on Jan. 28, 2014 and Jan. 30 and 31, 2019, happened due to extreme cold weather, with extreme low temperatures falling to minus 11 degrees Fahrenheit during 2014, and minus 18 degrees Fahrenheit during 2019. The closures on Dec. 2, 1974 and Jan. 26 and 27, 1978 were due to extreme snow accumulation.

Overall, according to NOAA data from weather stations in the Ann Arbor area, there have only been 25 days since 1960 where minimum temperatures reached below minus 10 degrees Fahrenheit. In that same time, there have been seven days where the daily snowfall was greater than 10 inches.

After evaluating winter weather data in conjunction with University closures, it is still unclear how the University makes such monumental decisions to reduce its operations due to extreme weather. This decision-making process will have to continue to evolve with our changing climate and technology, as is reflected in this weather data analysis.