We are now past the end of the meteorological winter, which consists of the months of December, January and February.
This season has been a remarkably mild one for most of its duration. With the exception of a week of desperate cold in mid-January, there was hardly any cold air to speak of in southern Wisconsin all winter. In fact, Madison was 9.5 degrees above normal for December, 3.5 degrees above normal for January (reduced because of the cold snap Jan. 14-21, during which the temperature was 14 degrees below normal!) and 11 degrees above normal for February.
All together this means we were 7.9 degrees above normal from Dec. 1 through Feb. 28. (We don’t count leap days.)
Over the wider region, this was the warmest winter in the past 132 years at a vast majority of locations throughout Wisconsin and Minnesota, and over northeast Iowa and most of northern Michigan.
As measured by the areal extent of air colder than minus 5 centigrade (23 Fahrenheit) at 850 millibars (about 1 mile above the surface), this was the third-warmest winter in the past 76 seasons, only slipping from second to third place on the last day of the tally, Feb. 28.
No matter how one looks at this winter — locally, regionally or hemispherically — it was one of the warmest in a century. Current guidance from the Climate Prediction Center suggests about a 50% chance of the unusual warmth persisting, though with some interruptions, through meteorological spring, March through May. We would not be surprised, however, to see at least a couple additional examples of winter before we finally see this mildest of winter seasons come to its end.
Steve Ackerman and Jonathan Martin, professors in the UW-Madison department of atmospheric and oceanic sciences, are guests on WHA radio (970 AM) at 11:45 a.m. the last Monday of each month. Send them your questions at stevea@ssec.wisc.edu or jemarti1@wisc.edu.
