Expanding on my previous comment, a few years ago, the lake levels were down a bit, and a bunch of people were screaming that the Lakes were in irrecoverable decline, and that the lake levels would never return to the average, commerce would be ruined, and massive and horrible dredging would have to take place. They ignored the fact that in the mid-1990s the Lake levels were well above normal, and the Gold Coast condos in Chicago along the Lake Michigan shoreline were having their garages flooded out by high waves.
The next year after all of this hysteria, we had a wetter-than-normal year, and the lake levels came roaring back, going to a foot above the normal average. Right now, the lakes are about a foot above normal. By the way, if I remember correctly, and I need to go back and find the correct cite, Great Lake water levels have only been monitored for about 100 years.
A trivia note. Prior to 1871, there were no official weather records maintained by the U.S. Government. In 1871, the U.S. Army Signal Corps were given the responsible for weather monitoring and weather forecasting. Reports were taking locally, typically by a sergeant, then coded and sent by telegraph to Washington, D. C., where they were decoded and logged in. In 1891, responsibility for weather reporting and forecasting was transferred to the U.S. Department of Agriculture, who had to take all of the information gathered by the Army, much of it hand-written, and record it in the system that they developed. There are some interesting articles in the Department of Agriculture yearbooks of around 1900 about the change-over, and the problems it entailed. The Army used a different temperature scale than the Agriculture Department as well. The end result is when someone talks about record or above normal temperatures, I take it with a fairly large grain of salt.
