U.S. Army Corps of Engineers
End-of-September Lake Levels
Lake Superior rose two inches in September and is now just two inches below its long-term average.
From the International Lake Superior Board of Control and the U.S. Army Corps of Engineers:
The monthly mean water level of Lake Superior in September was 601.97 feet, which is a rise of 2 inches from August’s level. Typically, Lake Superior’s September level is nearly the same as the August level. The September level was 11 inches above its level of a year ago, 10 inches above chart datum, and 2 inches below long‐term average (LTA). Lake Superior continues its 14 year stretch of below LTA water levels, the longest period of below average levels in its recorded history dating back to 1918. Precipitation on the Lake Superior basin was 73% of average in September, and 105% of average during the past 12 months.
The Superior level is expected to be 3 to 8 inches above chart datum through December and then continue dropping to 3 inches below datum by March 2014. The water levels are forecasted to be 9 to 12 inches above last year’s levels and 3 to 4 inches below LTA over the next six months.