Updated March 18th. Excepts from the Army Corps of Engineers – Detroit District’s Monthly and Weekly reports for Great Lakes Water Levels and Great Lakes Water Level History.
All The Great Lake Water Levels Continue To Drop From Record Levels
The projected water levels for April 2nd indicate that Lakes Superior and Michigan-Huron’s water levels are near their levels from a month ago, while Lakes St. Clair, Erie, and Ontario have risen by 2 to 3 inches since early March. Projected water levels for April 2nd across all the lakes are tracking below levels from one year ago. Compared to the average April monthly levels, the projected levels for April 2nd are above average on all lakes, except Lake Ontario. By May 2nd, water levels are forecast to rise by 2 to 4 inches on Lakes Superior, Michigan-Huron, St. Clair, and Erie, while Lake Ontario is forecast to rise by 6 inches.
Lakes Michigan-Huron Water Levels
On March 12th, Lake Huron had dropped 11 inches since March 2020, dropping two more inches during the past month. Levels were down 10 inches from March 2020 and eleven inches below the monthly high record set in 2020. Lake Huron remains at 54 inches above the record monthly low, set in 1964. The lakes are expected to rise by 2 inches in mid-April 2021. For reporting purposes, Lakes Michigan-Huron is the same body of water.
Lake Superior Water Level
As of April 2, 2021, the Lake Superior water level is forecasted to be 601.84 feet. This is 9 inches less than the high record water level set in 1986 and 28 inches higher than the lowest record set in 1926. Over the next month, Lake Superior is expected to rise 3 inches.
Early projects show that due to La Nina weather patterns of the past, Lake Superior may again approach record water levels during the Fall of 2021.
Lake St. Clair Water Level
As of April 2, 2021, Lake St. Clair’s water level is forecasted to be 576.02 feet. This is 13 inches less than the high record water level set in 2020 and 49 inches higher than the lowest record set in 1926. Over the next month, Lake St. Clair is expected to rise an aggressive 3 inches.
Lake Erie Water Level
As of April 2nd, 2021, Lake Erie’s water level is forecasted to be 572.87 feet. This is 13 inches less than the record high water level set in 2020 and 49 inches higher than the lowest record set in 1926. Over the next month, Lake Erie is expected to rise by 5 inches.
Lake Ontario Water Level
As of April 2nd, 2021, Lake Ontario’s water level is forecasted to be 244.62 feet. This is 43 inches less than the record high water level set in 1973 and 21 inches higher than the lowest record set in 1935. Over the next month, Lake Ontario is expected to rise by 6 inches.
April – May Downbound Outflows Expected To Be Above Average
Lake Superior’s outflow through the St. Marys River is predicted to be above average this April. Lake Michigan-Huron’s outflow through the St. Clair River and Lake St. Clair’s outflow into the Detroit River is forecasted to be above average for April. Lake Erie’s outflow into the Niagara River is predicted to be above average for April. Lake Ontario’s outflow through the St. Lawrence River is projected to be above average in April.
Long Term Great Lakes Water Level Estimates
The outlook from April 2021 for the next month by the Climate Prediction Center shows a possibility of above-normal temperatures for April. The forecast for rain in April is equal chances for most of the basin. This means an equal prospect of the basin enduring above, below, or near-normal precipitation. The seasonal three-month forecasts for temperatures and precipitation in the late spring and early summer (April, May, June) indicate a likelihood of above-normal temperatures and above-normal rain for all the Great Lakes basin. The seasonal outlook of above-normal precipitation can be partially credited to the ongoing La Niña. However, the La Niña conditions are forecast to transition to ENSO neutral later this spring.
Like January, the Great Lakes basin and each lake basin received below-average precipitation in February. Each lake received between 46% to 58% of its average February precipitation. Furthermore, precipitation in the Lake Superior, Erie, and Ontario basins has been around 16-20% below average over the past 12 months. Lake Superior received approximately four times its average water supply for February, while the other lakes received below-average supplies. An ice jam on the St. Clair River during the month likely impacted the water supply to Lake Erie. Outflows remained above average from all lakes due to the high-water level conditions; however, outflow through the St. Clair River was decreased by the ice restrictions.
From January to February, all lakes saw a decline in water levels. Lakes Superior and Michigan-Huron declined 3 inches, Lake St. Clair declined 6 inches, Lake Erie declined 5 inches, and Lake Ontario declined 4 inches from January to February. The water level declines on Lake St. Clair and Erie were influenced by the ice jam on the St. Clair River. The 6-month forecast projects Lakes Superior and Michigan-Huron to continue their seasonal declines over the next month while levels are expected to rise on Lakes St. Clair, Erie, and Ontario.
2020 Was A Record Year for the Great Lakes
This past August, La Niña conditions developed in the equatorial Pacific Ocean. This means that the sea surface temperatures in the eastern and central equatorial Pacific oceans are cooler than normal.
When this occurs, there can be impacts on the Great Lakes region’s weather, especially in the winter. The current forecast issued by the Climate Prediction Center expects that La Niña will last through the winter. The weather conditions that typically occur then a La Niña is present in the winter. For the Great Lakes basin, southern portions of the basin could experience wetter than normal conditions, and colder air could push further south into the region.
2020 Yearly Great Lakes Water Level History
Lake Michigan-Huron has set a record high monthly mean level for 9 consecutive months. Also, the August 2020 level was 4 inches above its August 2019 level and 33 inches above its August Long Term Average level.
Dynamic Great Lakes – Lake Level Viewer – From NOAA
Daily Great Lakes Water Level History
The report below is a view of long-term, basin-scale hydrological data for the Laurentian Great Lakes. Water levels are continuously observed by U.S. and Canadian federal agencies in the region through binational cooperation. NOAA-GLERL relies on this water level data to conduct research on the regional water budget components and improve predictive models.
NOAA’s Center operates water level monitoring stations for Operational Oceanographic Products and Services and the Department of Fisheries and Oceans’ Canadian Hydrographic Service. The U.S. Army Corps of Engineers (Detroit, Chicago, Buffalo) and Environment and Climate Change Canada play crucial roles in research, coordination of data, and operational seasonal water level forecasts for the basin.