The winter severity index for the International Falls area reached 119 on Thursday, reports Larry Petersen, Minnesota Department of Natural Resources International Falls area wildlife manager.
The WSI for the area was 106 last year at this date, and 111 two years ago, he notes.
The average WSI for this date is about 106; borderland’s harshest winter in the mid 90’s had an index of 179 on this date.
The snow remains deeper than normal for this time of year, and ranges from 16 to 21 inches in the International Falls vicinity. On average the area has about 14 inches by this date. The snow conditions continue to be a concern for deer survival as winter progresses. As snow melts and freezes a crust can be formed that can support predators but not deer.
All the winter severity data dates from 1966 to present.
The winter severity index is a standardized number resource managers use when considering impacts of the winter on deer. It is calculated using temperature and snow depth in the period from Nov. 1 through April 30 or whenever winter ends. Every day the daily low temperature is zero or below is one point, and every day the snow depth is 15 inches or deeper in an open aspen woods is one point. The points are added each week until winter ends.
Statewide WSI information for the current and past few years along with a variety of deer management information can be found at the DNR website: https://www.dnr.state.mn.us/mammals/deer/management/statistics.html