November truly begins the slide into winter for the Upper Peninsula. No other month has such a precipitous fall in average temperature. By the end of the month, most locations except possibly the far south have a snow cover that lasts through the winter.
The average high on November 1 at the National Weather Service (NWS) near Negaunee is 45, while the average low is 29. By the 30th, the averages plunge to 31 and 17. Shirtsleeve weather is possible early in the month. The high at the NWS topped out at 73 as late as November 9, 1999. The same year Ironwood hit 71 on the 10th, while on November 14 in 1999 and 1953 Iron Mountain topped out at 70. During the days leading up the infamous ??Edmund Fitzgerald Storm?? in 1975, downright balmy weather prevailed for a week. From November 2-8, the mean temperature in Marquette came in 17.3 degrees above average. As the warm spelled faded, the storm moved out of the Rockies on the 8th, and then came northeastward while deepening. The ??Fitz?? sank on the evening of November 10, 1975 as the strongest winds and waves blasted the ship as her captain raced for the shelter of Whitefish Bay.
By the latter portion of November, record lows are below zero. In fact starting on November 7th, all of Ironwood??s record lows are below zero, with an all-time November low of 18 below set on November 30, 1976. Yesterday, it was pointed out that recent Novembers have been warm. In fact, the last below zero lows in November at the NWS go back seven years. On November 25-26, 2005, lows went to 4 below and 8 below respectively. Of course, there was a foot of snow on the ground.
This November has started cold, but will the cold hold? Typically, the month exhibits a lot of variability, so some warm spells are likely. However, the fall so far has shown a tendency for colder-than-average weather. Looking ahead, it appears that some very cold air will develop in Canada toward mid-month (Image 1 above). This a much different scenario than what occurred last November (Image 2), when mild westerly flow dominated the United States and southern Canada.