As a result of unusually heavy precipitation, the water level in Lake Superior has increased rapidly in the last year, by about 14 inches (based upon 3 month averages). This rate of rise is the fastest 12-month increase ending in April-May-June average levels since 1916, and the 2nd fastest since records began in 1860 (154 years ago). An Excel spreadsheet with the data is here.

Here’s a plot of monthly departures from the long-term average (deseasonalized):

Monthly departures from average of Lake Superior water levels between 1860 and June 2014.

As a result of the high lake levels, water flow out of Superior through the St. Marys river in Sault Ste. Marie, MI, has been increased by increasing the number of gates open.

As discussed by Steve Hayward today, this rise in lake levels was totally unexpected by climate scientists, who have been anticipating declining lake levels in response to global warming-induced drought.

Of course, those scientists will no doubt claim they will eventually be proved correct. Except that climate models they rely upon are notoriously poor at predicting regional changes in climate…even worse than predicting changes in global-average conditions.