A January 2014 Governing article describes the challenges associated with the unpredictability of snow storms and the havoc it creates for local government budgets.
Predicting just how much a local government will need to spend for the upcoming winter is only a best guess. Costs vary widely from year to year, depending not only on the severity of the weather, but where on the calendar storms fall and even the time of day a storm hits.
The article points out that most local governments tend to plan for an average year, but find most years are not average in terms of snow fall increasing costs. Snow storms that occur on weekends can be extremely costly as road crews are paid overtime.