A record high of 43 was set on January 7, 2003 at the National Weather Service (NWS) near Negaunee.  The next day, a high of 48 degrees was observed.  This warmth was the culmination of an extended mild spell that began just before Christmas. 

The 2002-03 season started cold.  A major pattern shift brought chilly Polar air into Upper Michigan in late October (Image 1 above).  The cold deepened into November and by deer hunting season, many places had morning lows well below zero.  Then during the second week of December, the pattern shifted and mild Pacific air flooded the northern tier of states and temperatures popped well above average.  The peak of the warm spell occurred early the second week of January 2003 (Image 2).  The mean temperature on the 7^th and 8^th was 25 degrees above average. 

The pattern began to change by January 10.  Cold air filtered in, and by late in the month, the Upper Peninsula was in the grip of arctic air.  The last half of the month saw nine days with temperatures zero or below.  The cold deepened in February, and by early March, Lake Superior was virtually frozen over.  The winter of 2002-03 was the coldest of the early 21^st century. 

A thaw is now in full swing across the U.P.; actually, there has been no real winter cold yet in the winter of 2012-13.  “Officially”, there have still been no subzero readings at the NWS this winter.  This current mild weather will continue through the end of the week.  There may even be a little rain Thursday night into Friday as a system spinning over Old Mexico lifts to the northeast ahead of a developing upper-air trough out West (Images 3 and 4).  At the same time, cold air will be reloading in Canada.  This time, it looks like the atmosphere will align in such a way to bring a slug of that frigid air south into the United States during next week.