It hit 30 degrees below zero at the National Weather Service (NWS) site near Negaunee early on the morning of March 3, 2003. This reading stands as the coldest March temperature recorded at the site. The first ten days of March 2003 was an incredible 16 degrees below the long-term mean. The severe cold held on until just before mid-month and then a remarkable turn-around in temperature occurred. From the 14th to the 25th, the mean temperature was 11.6 degrees above average.
Because of the warmth, the winter snow cover was gone by March 25, but winter wasn??t over. A 15-inch snowstorm occurred on March 27-28; more snow fell and then below zero temperatures returned at the end the month. True winter extended into early April. Twenty inches of snow fell from the 2nd to the 5th. Then the temperature hit a low of 9 below on the 6th??the coldest ever recorded at the NWS.
The bitter beginning to March 2003 was the result of a huge pool of cold air that developed over Canada during the heart of winter. The cold pool, represented by a huge polar vortex, was tenacious during the latter part of that winter and early spring.
This year, the pattern at the start of March was roughly similar. The cold pool of air brought 30 below readings to a number of locations early this morning. They included Champion and Garden Corners (-30), Amasa, Watersmeet and Spincich Lake (-31), Stonington (-33) and Wakefield (-34). This is probably the last night we??ll see readings this cold; not because of some great pattern flip to warm but because as we move farther into March, even if a cold pattern hangs on, shorter nights and higher sun angle argues for gradual moderation.