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Great Lakes Water Level Outlook- October 2020 Edition - November Update

Outlook Summary:

This product is not an official forecast of Great Lakes water levels. Rather, this product is meant to illustrate outcomes that would occur under historical weather and water supply condition, with scenarios chosen based on similarities to recent conditions. For the official forecast, please see our Monthly Bulletin of Great Lakes Water Levels.

 

Near or above record high water levels continue on some of the Great Lakes. Water levels follow a seasonal cycle where water levels rise in the spring due to increased precipitation and enhanced runoff from snowmelt. In the fall, the lakes generally decline due to an increase in evaporation as temperatures decline and cold air moves over the relatively warm lake waters. We refer to the combined effect of precipitation over the lake, evaporation from the lake, and runoff to the lake as Net Basin Supply (NBS). This edition of the Water Level Outlook shows a purple plume that represents NBS sequences from years when a La Niña developed in the prior spring, summer, or fall and lasted through the winter. Two years within the plume have been specifically called out to evaluate what occurred during those years compared to 2020. These two years are 2005-06 and 2010-11. The green line represents the water levels that would occur if the same NBS sequence were to occur in 2005-06 over the next 12 months. The blue line represents water levels that would result if the NBS sequence from 2010-11 were to reoccur over the next 12 months. The most recent coordinated 6-month forecast is also shown for comparison.



Click on the individual graphics to view a larger, printer-friendly image (pdf).


12-Month Outlook Legend

 
Lake Superior 12-Month Outlook Graphic Lakes Michigan-Huron 12-Month Outlook Graphic
Lake St. Clair 12-Month Outlook Graphic Lake Erie 12-Month Outlook Graphic


12-Month Outlook Legend
 
 
* For the official 6-month forecast of all lakes, including Lake Ontario, see the Monthly Bulletin of Great Lakes Water Levels.
 

 

Click here to obtain the full Great Lakes Water Level Outlook document (pdf)

Great Lakes Water Level Outlook Data

 

To view the water level outlook data in tabular format, click on the links below.

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Lake Superior

Monthly Mean Water Level (meters IGLD)

  Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21 Jul-21 Aug-21 Sep-21 Oct-21
Maximum La Nina 183.77 183.76 183.69 183.62 183.56 183.59 183.70 183.81 183.87 183.93 183.91 183.90
Minimum La Nina 183.68 183.59 183.49 183.42 183.35 183.37 183.45 183.53 183.61 183.59 183.50 183.42
2005-2006 183.72 183.66 183.58 183.51 183.46 183.48 183.55 183.61 183.62 183.59 183.50 183.42
2010-2011 183.70 183.60 183.50 183.42 183.35 183.37 183.48 183.59 183.66 183.67 183.63 183.57
Long Term Average 183.47 183.41 183.33 183.27 183.24 183.26 183.37 183.45 183.51 183.54 183.54 183.52
Long Term Maximum 183.89 183.81 183.70 183.63 183.61 183.68 183.77 183.84 183.86 183.86 183.86 183.91
Long Term Minimum 183.01 182.92 182.83 182.76 182.74 182.72 182.76 182.85 182.96 183.01 183.02 183.10

 

 

Lake Michigan-Huron

Monthly Mean Water Level (meters IGLD)

 

  Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21 Jul-21 Aug-21 Sep-21 Oct-21
Maximum La Nina 177.25 177.25 177.20 177.16 177.25 177.39 177.50 177.51 177.48 177.46 177.43 177.40
Minimum La Nina 177.15 177.04 176.99 176.94 176.93 176.97 177.00 177.04 177.06 176.98 176.85 176.75
2005-2006 177.19 177.13 177.11 177.11 177.11 177.15 177.22 177.24 177.22 177.16 177.05 176.97
2010-2011 177.17 177.07 176.99 176.94 176.93 177.03 177.18 177.27 177.29 177.24 177.15 177.08
Long Term Average 176.39 176.35 176.30 176.29 176.31 176.39 176.49 176.56 176.59 176.57 176.52 176.45
Long Term Maximum 177.38 177.26 177.18 177.11 177.12 177.23 177.28 177.33 177.39 177.39 177.38 177.50
Long Term Minimum 175.65 175.61 175.57 175.59 175.58 175.61 175.74 175.76 175.78 175.77 175.76 175.70

 

 

Lake St. Clair

Monthly Mean Water Level (meters IGLD)

 

  Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21 Jul-21 Aug-21 Sep-21 Oct-21
Maximum La Nina 175.71 175.73 175.68 175.74 175.92 176.01 176.01 176.04 175.98 175.91 175.90 175.86
Minimum La Nina 175.59 175.50 175.53 175.50 175.52 175.57 175.59 175.59 175.57 175.50 175.39 175.29
2005-2006 175.65 175.65 175.66 175.70 175.72 175.73 175.77 175.78 175.78 175.74 175.63 175.61
2010-2011 175.64 175.61 175.53 175.50 175.69 175.82 176.01 176.04 175.98 175.88 175.80 175.75
Long Term Average 174.93 174.93 174.85 174.80 174.92 175.06 175.14 175.19 175.21 175.17 175.10 175.01
Long Term Maximum 175.82 175.80 175.80 175.80 175.80 175.82 175.89 175.99 176.04 175.96 175.86 175.96
Long Term Minimum 174.18 174.24 173.88 173.89 174.05 174.32 174.42 174.45 174.50 174.41 174.34 174.27

 

 

Lake Erie

Monthly Mean Water Level (meters IGLD)

 

  Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21 Jul-21 Aug-21 Sep-21 Oct-21
Maximum La Nina 174.73 174.79 174.80 174.88 175.06 175.17 175.24 175.28 175.16 175.04 174.94 174.89
Minimum La Nina 174.61 174.51 174.55 174.58 174.62 174.70 174.74 174.70 174.65 174.56 174.44 174.33
2005-2006 174.67 174.69 174.74 174.79 174.82 174.86 174.90 174.90 174.92 174.90 174.78 174.71
2010-2011 174.66 174.62 174.57 174.58 174.78 175.04 175.24 175.28 175.16 175.03 174.94 174.89
Long Term Average 174.01 174.01 174.01 174.00 174.09 174.24 174.32 174.35 174.34 174.27 174.18 174.08
Long Term Maximum 174.85 174.89 174.86 174.78 174.88 174.98 175.05 175.14 175.13 175.02 174.87 174.94
Long Term Minimum 173.20 173.19 173.21 173.18 173.20 173.38 173.44 173.45 173.45 173.43 173.38 173.30

 

Lake Superior

Monthly Mean Water Level (ft IGLD)

  Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21 Jul-21 Aug-21 Sep-21 Oct-21
Maximum La Nina 602.92 602.90 602.66 602.43 602.24 602.32 602.70 603.04 603.25 603.43 603.39 603.34
Minimum La Nina 602.64 602.34 602.00 601.76 601.56 601.61 601.86 602.14 602.39 602.33 602.04 601.76
2005-2006 602.74 602.55 602.30 602.08 601.91 601.96 602.21 602.39 602.43 602.33 602.04 601.76
2010-2011 602.68 602.35 602.02 601.78 601.56 601.61 601.97 602.32 602.56 602.60 602.45 602.26
Long Term Average 601.94 601.74 601.48 601.28 601.18 601.25 601.61 601.87 602.07 602.17 602.17 602.10
Long Term Maximum 603.31 603.05 602.69 602.46 602.40 602.62 602.92 603.15 603.22 603.22 603.22 603.38
Long Term Minimum 600.43 600.13 599.84 599.61 599.54 599.48 599.61 599.90 600.26 600.43 600.46 600.72

 

 

Lake Michigan-Huron

Monthly Mean Water Level (ft IGLD)

 

  Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21 Jul-21 Aug-21 Sep-21 Oct-21
Maximum La Nina 581.54 581.54 581.35 581.25 581.52 581.99 582.34 582.38 582.29 582.21 582.12 582.02
Minimum La Nina 581.19 580.84 580.68 580.50 580.47 580.59 580.72 580.84 580.92 580.66 580.23 579.89
2005-2006 581.35 581.12 581.06 581.07 581.06 581.20 581.42 581.49 581.43 581.25 580.89 580.62
2010-2011 581.26 580.94 580.68 580.50 580.47 580.81 581.30 581.60 581.67 581.50 581.19 580.96
Long Term Average 578.71 578.58 578.41 578.38 578.44 578.71 579.04 579.27 579.36 579.30 579.13 578.90
Long Term Maximum 581.96 581.56 581.30 581.07 581.10 581.46 581.63 581.79 581.99 581.99 581.96 582.35
Long Term Minimum 576.28 576.15 576.02 576.08 576.05 576.15 576.57 576.64 576.71 576.67 576.64 576.44

 

 

Lake St. Clair

Monthly Mean Water Level (ft IGLD)

 

  Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21 Jul-21 Aug-21 Sep-21 Oct-21
Maximum La Nina 576.47 576.54 576.38 576.58 577.17 577.46 577.45 577.57 577.38 577.12 577.10 576.97
Minimum La Nina 576.09 575.80 575.88 575.77 575.85 576.00 576.07 576.08 576.01 575.78 575.42 575.10
2005-2006 576.27 576.28 576.30 576.43 576.49 576.53 576.68 576.69 576.70 576.58 576.22 576.13
2010-2011 576.24 576.15 575.90 575.77 576.40 576.84 577.45 577.57 577.38 577.03 576.77 576.60
Long Term Average 573.92 573.92 573.65 573.49 573.88 574.34 574.61 574.77 574.84 574.70 574.48 574.18
Long Term Maximum 576.84 576.77 576.77 576.77 576.77 576.84 577.07 577.40 577.56 577.30 576.97 577.30
Long Term Minimum 571.46 571.65 570.47 570.51 571.03 571.92 572.24 572.34 572.51 572.21 571.98 571.75

 

 

Lake Erie

Monthly Mean Water Level (ft IGLD)

 

  Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21 Jul-21 Aug-21 Sep-21 Oct-21
Maximum La Nina 573.25 573.46 573.49 573.74 574.35 574.70 574.93 575.06 574.68 574.28 573.93 573.78
Minimum La Nina 572.86 572.54 572.66 572.78 572.89 573.17 573.30 573.16 573.00 572.70 572.29 571.96
2005-2006 573.08 573.12 573.30 573.46 573.56 573.69 573.80 573.82 573.87 573.81 573.41 573.20
2010-2011 573.03 572.90 572.75 572.78 573.43 574.27 574.93 575.06 574.68 574.23 573.93 573.78
Long Term Average 570.90 570.90 570.90 570.87 571.16 571.65 571.92 572.01 571.98 571.75 571.46 571.13
Long Term Maximum 573.65 573.79 573.69 573.43 573.75 574.08 574.31 574.61 574.57 574.21 573.72 573.95
Long Term Minimum 568.24 568.21 568.27 568.18 568.24 568.83 569.03 569.06 569.06 569.00 568.83 568.57

 

Detroit District Disclaimer

NOTICE: All data contained herein is preliminary in nature and therefore subject to change. The data is for general information purposes ONLY and SHALL NOT be used in technical applications such as, but not limited to, studies or designs. All critical data should be obtained from and verified by the United States Army Corps of Engineers, Detroit District, Engineering and Technical Services, Great Lakes Hydraulics and Hydrology Office, 477 Michigan Ave., Detroit, MI 48226. The United States of America assumes no liability for the completeness or accuracy of the data contained herein and any use of such data inconsistent with this disclaimer shall be solely at the risk of the user.