Indian Agent Henry Rowe Schoolcraft was transferred from Sault Ste. Marie to Mackinac Island late in 1833. He resolved to keep himself occupied during the long winter "with notices of...(Mackinac Island's)...meteorology, the changes of wind and currents in the straits" and so on.
On January 8, 1834, Schoolcraft noted "snow-blustering coldâ?? (we certainly can relate to his description, especially the blustery part this winter) By January 13, snow drifts made for difficult travel around the island. This was the first genuine bout of winter weather during the warm season of 1833-34. Travel was also impeded on the water surrounding Mackinac due to the unseasonable warmth. The harbor and straits remained mostly ice-free until the last few days of December. Then as the weather finally grew colder, floating ice became a problem. On January 6 Schoolcraft wrote, â??Indians, detained by floating ice since New Yearâ??s, got over to Pt. St. Ignace.â?? By the 14th, ice completely filled the channel between Bois Blanc and the main harbor, though the outer channel remained open.
A thaw occurred on January 16 with rain that continued all evening. Schoolcraft was out visiting late that day and recalled that he â??got a complete wettingâ?? on the way home. On the 17th, he noted that the rain â??much diminished the quantity of snow; bare ground is to be seen in some spots.â?? In the wake of the rainstorm, Schoolcraft observed the air was â??murky, and surcharged with moisture, rendering it disagreeable to be out of doors.â??
Fort Snelling also had rain and a thaw on the 16th but by the 17th winter began closing in again. Colder air did not reach Mackinac until the 18th, when Schoolcraft reported a â??depression of the atmospheric temperature.â?? The ice made â??walking slippery and the snow crusted and hard.â?? He was told the crusted snow â??was fatal to wild hoofed animals, which at every step are subject to break through, and cut their ankles.â?? This fact was good news for the Indians who â??successfully pursue and take the moose and reindeerâ?? when the snow is crusted over by a thaw and subsequent freezing.
The last part of January 1834 saw the only true bitter period of the winter. Arctic air began flowing over the open waters of the Great Lakes on the 19th and led to snow. The snow was attended by a west wind, which made the day â??very blustering and boisterous.â?? The wind was â??so strong as to blow some persons down.â?? The next day the temperature stood at only 2 degrees above zero at 8 in the morning. By the 24th the temperature at the fort had fallen to 5 below, while in Minnesota the lowest reading of 32 below was reached, attesting to the moderating influence of the Great Lakes.
Schoolcraft was an astute observer of lake-effect. He noted â??the airâ?|became colder than the water of the lake, producing an interchange of temperature, and the striking phenomenon of rising vapor.â?? He went on to explain, â??The open waters gave out their latent heat, like a boiling pot.â?? Schoolcraft stated he observed this spectacle â??in the basin of the Upper Lakes, some days every winter.â?? The mechanism he described occurs only when the air flowing over the water is cold enough to lead to evaporation. It is this process that leads to heavy snows on the lee shores of the Great Lakes during the fall and winter months.
Schoolcraft probably saw no â??rising vaporâ?? off Lake Huron for much of the rest of the winter. After the cold start on the 24th the temperature began to moderate. By the last day of January 1834 he wrote, â??The sun shone clear; no snow; no high winds, but a serene and pleasant atmosphere.â?? February was exceptionally mild. Even when it cooled down briefly on the 7th, the temperature only slipped to 26 degrees. After snow and a brief cool-down on the 16th and 17th, the weather turned even warmer. Rain began on the 19th accompanied by spring-like thunder on the 20th. In Minnesota, February 1834 was the warmest second month of the pioneer era, averaging an incredible sixteen degrees above normal.
The first week of January 2014 is averaging over 16 below normal. Through the first week, the average high was only 6 degrees and the average low 10 below. As for ice, the bays around the Great Lakes are frozen over and ice continues growing (Image 1 & 2 above). A break in the bitter cold is on the way. It will gradually warm up into the weekend and, right now, it appears that the moderate temperatures will continue at least into the middle of next week.