This dashboard was designed for convenience in examining Great Lakes water levels and forecasts at a variety of time scales. Please direct questions or feedback to:
Anne H. Clites, Physical Scientist
NOAA Great Lakes Environmental Research Laboratory
4840 S. State Rd, Ann Arbor, MI 48108
Dr. Drew Gronewold, GLERL Research Hydrologist
The Great Lakes Climate Dashboard is sponsored by the Great Lakes Restoration Initiative (GLRI), the Cooperative Institute for Limnology and Ecosystems Research (CILER), and the Great Lakes Environmental Research Laboratory (GLERL), part of the National Oceanic and Atmospheric Administration (NOAA).
Lastly, thanks to Cathy Darnell at GLERL for consultation on graphics, and for earlier inspiration, a special thanks to Mark Phillips, creator of Multigraph.
DISCLAIMER: This page contains links to non-Federal government web sites. They do not constitute endorsement of any product, service, organization, company, information provider, or content.
The Great Lakes Water Level dashboard was designed to help users view, understand, and compare Great Lakes surface water elevation data and forecasts from a variety of different sources, and across a variety of time scales ranging from monthly average values, to annual and multi-decadal values. For Great Lakes water level data and forecasts at a higher temporal resolution, we direct users to the NOAA National Ocean Service (NOAA-NOS) Great Lakes water level gauging station site, the Canadian Hydrographic Service site, and the NOAA-NOS Great Lakes Operational Forecasting System site.
The following is a list of tips to help navigate the dashboard:
The water levels in the Great Lakes are monitored by NOAA - National Ocean Service in the U.S. (Center for Operational Oceanographic Products and Services) and by the Canadian Hydrographic Service in Canada. Water levels shown here are lakewide monthly averages. Data is available for individual water level gauges and at a higher resolution (daily, 6-minute average) by going to the source agency's websites shown above.
1918-present: monthly lakewide average water levels
In 1992, the Coordinating Committee for Great Lakes Basic Hydraulic and Hydrologic Data approved a set of gauges (U.S. and Canadian) for each lake that water resource professionals believe give the most accurate reflection of the lake's overall water level when averaged. These lakewide average levels are used by the Army Corps of Engineers and Environment Canada in their forecast bulletins. The gauge networks are as follows, with the underlined gauges indicating the master gauges (well established gauges used in the development of lake datum):
|Lake Superior||Lake Michigan-Huron||Lake St. Clair||Lake Erie||Lake Ontario|
|Duluth, MN||Ludington, Mackinaw City, Harbor Beach, MI||St. Clair Shores, MI||Toledo, Cleveland, OH||Rochester, Oswego, NY|
|Marquette, Pt Iroquois, MI||Milwaukee, WI||Belle River, ON||Port Stanley, Port Colborne, ON||Port Weller, Toronto, Cobourg, Kingston, ON|
|Michipicoten, Thunder Bay, ON||Thessalon, Tobermory, ON|
Before 1918, there were very few water level gauges in the Great Lakes. However, Superior, Michigan, Huron, Erie, and Ontario all have at least one water level gauge that has been in operation since 1860. They include the gauges considered to be the "master gauges" on each lake. Because of isostatic rebound (shifting of the land surface following the retreat of the glaciers), the levels at these gauges may not represent the lake-wide average level if they are far from the lake's outlet. These historical levels can be adjusted to represent the levels at the outlet. You may compare the adjusted levels (1860-1917) to the original measurement on Superior and Erie by viewing the master gauge and the adjusted monthly average time series (diamonds and triangles respectively). The equations used to adjust these early gauge records are:
|Superior||Marquette||To Pt Iroquois: PI = -.00108382*year+2.153 + Marquette|
|St. Clair||Gross Pointe Yacht Club||None|
|Erie||Cleveland||To Buffalo: Buff = -.001008382*year+2.153 + Cleveland|
Per month averages and record highs and lows for each month are available for the lake-wide average water levels (1918-present). These values are coordinated by the U.S. Army Corps of Engineers and Environment Canada. Data are here in meters, and here in feet.
Additional perspective on Lake Michigan-Huron water levels is provided by this pre-1860 monthly water level data set recorded in Milwaukee, Wisconsin between 1815 and 1859, encompassing a period of high water levels in 1838. These data were adjusted to the outlet at Harbor Beach to account for isostatic rebound and translated from the Lake Survey Datum of 1877 to IGLD 1955. The data set was updated to IGLD 1985 using a Harbor Beach correction of 0.214 meters.
These water level forecasts were produced by GLERL's Advanced Hydrologic Prediction System (AHPS) model. GLERL's forecast probability bands for both 3-month (dark) and 6-month (light) forecasts can be shown on the dashboard by checking the appropriate menu boxes. The colored bands show the 90% probability intervals for the month's mean water level. If AHPS was always accurate, these bands would contain the observed water level 90% of the time. GLERL recently started archiving AHPS' forecasts in order to assess its performance. A recent study (Gronewold 2011) showed that the 90% probability band captures between 64 and 74% of the observed water levels, based on the years 1997 through 2009.
More about GLERL's seasonal water level forecast model
The NOAA Great Lakes Environmental Research Laboratory produces a new water level forecast for from one to ten months in the future every day. The GLERL forecast is a research tool, not associated with any operational decisions, however, it is relied on by many governmental agencies and others who need water level information for planning. GLERL's Advanced Hydrologic Prediction System combines historical meteorological data with a series of mathematical models and climate forecasts from NOAA's Climate Prediction Center to simulate multiple hydrologic variables (precipitation, runoff, evaporation). The net 'supply' of water to each basin is routed through the lakes and their connecting channels to produce predicted monthly levels. More information about GLERL's water level forecasts and access to the daily update can be found here.
Croley, T., Lee, D., 1993. Evaluation of Great Lakes net basin supply forecasts. J. Am. Water Resources Association 29(2), 267-282
Croley, T., 1992. Long-term heat storage in the Great Lakes. Water Resources Research 28(1), 69-81.
Croley, T., Hartmann, H., 1985. Resolving Thiessen polygons. J. Hydrology 76(3-4),363-378
Other forecasts available
Several different agencies produce seasonal forecasts for Great Lakes water levels. The U.S. Army Corps of Engineers - Detroit District and Environment Canada have operational responsibilities related to the regulatory authorities for Lake Superior and Lake Ontario. The Corps of Engineers and Environment Canada collaborate to arrive at a single coordinated forecast for the lakes based on the lakewide average levels. Their forecast bulletins are published each month and widely distributed to basin residents.
Many studies have been published in the past several decades that use models to assess the impact future climates will have on Great Lakes water levels. Although a thorough understanding of each study will require reading the source material, the dashboard allows us to put these different projections side by side for visual comparison.
The long term water level projections presented here are from four recent studies:
Click the buttons below for more information on the individual studies' data.
This study used global climate model results from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, AR4. Three emission scenarios (high, intermediate, and low) were chosen and many runs were completed for each scenario; 565 in all. Between 18 and 23 general circulation models was used for each scenario. GLERL's AHPS was used to determine final lake levels. The base period for this study was 1970-1999. Projected lake levels were reported relative to the average lake level from the base period. Only the extreme emissions scenario projections are reported. The range shown is from 25th (bottom) to 75th (top) percentile.
Hayhoe et al. used both high (Special Report on Emissions Scenarios - SRES - A1fi) and low (B1) emissions scenarios to project future climate. Only the high emission scenario was used to plot change in lake levels (Fig 10 in the reference). Since the data was not available in digital form, values were carefully estimated from this graph. GLERL's Large Basin Runoff Model (LBRM, details here) and Advanced Hydrologic Prediction System were used to generate runoff and resulting lake levels. The base period for these projections is 1961-1990. Hayhoe et al developed projections for 3 time periods: 2010-2039, 2040-2069, and 2070-2099.
Lofgren et al. developed a new approach for estimating potential evapotranspiration by using an energy budget-based approach instead of the more common method of using air temperature as a proxy for evapotranspiration. Lofgren's base case is 1958-2005. Using two different climate models and two methods (details below) for calculating potential evapotranspiration yielded 5 projections:
Climate Models Used:
Both methods employ the GLERL Large Basin Runoff Model and were transformed to lake levels using the Coordinated Great Lakes Regulation and Routing Model.
This paper proposes a new method for estimating future net basin supplies and lake levels based on a bias-correction method that enables the direct use of general circulation model output to run evaporation and runoff models, preserving the land surface-atmosphere feedback loop. The general circulation model used here is the Canadian Regional Climate Model (GLRCM). The base period for this study is 1962-1990. Projections are made for the period 2021-2050. Results for the upper lakes are given in terms of lake level change relative to the base period.
Although the 150+ years of recorded water level data for the Great Lakes comprise one of the longest high quality hydrometeorological data sets in North America, it may not necessarily be representative of the last several thousand years during which the Great Lakes have been in their present hydraulic state. Records from paleo lake level analysis, using submerged tree stumps, tree ring data, and ancient shorelines to draw conclusions about past lake levels, climate, and glacial isostatic adjustment, can add context to both our understanding of current lake level fluctuations as well as our attempts to project how future climates and vertical ground movement will impact these levels.
These historical data are from the following journal articles:
"A Reconstruction of Lake Michigan - Huron Water Levels Derived from Tree Ring Chronologies for the Period 1600-1961", Frank H. Quinn and Cynthia E. Sellinger, Journal of Great Lakes Research 32:29-39, 2006
"A 265-year Reconstruction of Lake Erie Water Levels Based on North Pacific Tree Rings", Gregory C. Wiles, Anne C. Krawiec, and Rosanne D. D'Arrigo, Geophysical Research Letters, Volume 36, 2009
"A 4,700-year record of lake level and isostasy for Lake Michigan", Steve J. Baedke and Todd A. Thompson, Journal of Great Lakes Research, 26(4):416-426, 2000.
"A Sault-outlet-referenced mid-to-late Holocene paleohydrograph for Lake Superior constructed from strandplains of beach ridges", John W. Johnston, Erin P. Argyilan, Todd A. Thompson, Steve J. Baedke, Kenneth Lepper, Douglas A. Wilcox, and Steven L. Forman, Canadian Journal of Earth Sciences, 49:1-17, 2012
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