Weekly Water Levels Forecast
New! Update for Friday April 15, 2015 (includes data summary)

Weather conditions: The Great Lakes Basin received precipitation several days last week, which contributed to the slightly above average month to date precipitation total of 1.02 inches. Temperatures were colder to start the week throughout the Great Lakes Basin and gradually warmed up later in the week. Heading into the weekend, expect clear skies and warm temperatures throughout the basin. That trend will continue throughout the lower basin heading into the workweek, while some precipitation and lower temperatures are expected in the Lake Superior Basin on Monday.

Lake Level Conditions: Lake Superior is 1 inch higher than it was a month ago. Lakes Michigan-Huron, St. Clair, Erie and Ontario are in the midst of their seasonal rise and are 7 to 8 inches above what they were a month ago. All lakes are above their average levels of a year ago; Lake Superior is 2 inches higher, Lakes Michigan-Huron, St. Clair, and Erie are 10 to 15 inches higher, and Lake Ontario is 20 inches higher than they were at this time last year. All of the lakes are forecasted to rise 2 to 4 inches over the next 30 days. See the Daily Levels page for more water level information.

Forecasted outflows / channel conditions: Lake Superiorís outflow through the St. Maryís River is projected to be above average for the month of April. Lake Michigan-Huronís outflow into the St. Clair River and Lake St. Clairís outflow into the Detroit River are expected to be above average in April. Moreover, the April outflow of Lake Erie into the Niagara River is forecasted to be above average, and outflow of Lake Ontario into the St. Lawrence River is predicted to be above average in April.

Alerts: Official records are based on monthly average water levels and not daily water levels. Users of the Great Lakes, connecting channels and St. Lawrence River should keep informed of current conditions before undertaking any activities that could be affected by changing water levels. Mariners should utilize navigation charts and refer to current water level readings.