2019-May-16
May 11th Water Levels Report
Cold fronts and low pressure systems moved across the Great Lakes basin last week, which brought a drop in temperatures and rain. Low temperatures in the northern portions of the basin were near the freezing mark and prompted Freeze Warnings and Frost Advisories in some regions.
The recent wet conditions have caused water levels to climb and currently, water levels across the basin are 8 to 12 inches above last year’s water levels at this time. In the past month, all of the Great Lakes have experienced rises in water level with Lakes Superior, Michigan-Huron, St. Clair, Erie and Ontario rising by 5, 8, 12, 11, and 20 inches, respectively. The water levels of Lakes St. Clair and Erie are currently 4 inches above their record high monthly mean level for May, while Lake Superior is 1 inch below its May record high level. The projected levels for a month from now indicate Lakes Superior, Michigan-Huron, and Ontario rising by 4, 3, and 7 inches, respectively.
Lake Superior’s outflow through the St. Mary’s River, and Lake Michigan-Huron’s outflow into the St. Clair River, are forecasted to be above average in May. Outflows from Lake St. Clair through the Detroit River are also predicted to be above average.
