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Weekly Great Lakes Water Levels

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Weekly Forecast

WEEKLY GREAT LAKES WATER LEVEL UPDATE

August 22, 2014

 

WEATHER CONDITIONS

An active weather pattern brought significant rainfall to much of the Great Lakes basin this week.  In fact, all of the Great Lakes have received above average precipitation during August.  Unsettled weather will persist through the weekend and into next week, bringing the threat for more heavy rainfall in some portions of the basin.  Some locations may see torrential downpours and flash flooding.

LAKE LEVEL CONDITIONS

Lakes Superior and Michigan-Huron are both an inch above their levels of a year ago, while Lake St. Clair is near its level from a year ago.  Lakes Erie and Ontario are 2 and 5 inches, respectively, below what they were at this time last year.  Lakes Superior and Michigan-Huron are each predicted to fall an inch over the next 30 days.  Lakes St. Clair, Erie and Ontario, are projected to fall 3, 4, and 7 inches, respectively over the next month.  See our Daily Levels web page for more water level information.

FORECASTED MONTHLY OUTFLOWS/CHANNEL CONDITIONS

Lake Superior’s outflow through the St. Mary’s River is forecasted to be well above average for the month of August.  Lake Michigan-Huron’s outflow into the St. Clair River and Lake St. Clair’s outflow into the Detroit River are predicted to be near average in August.  In addition, the outflow of Lake Erie into the Niagara River and Lake Ontario’s outflow into the St. Lawrence River are projected to be above average in August.

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.

SUPERIOR

MICH-HURON

ST. CLAIR

ERIE

ONTARIO

Forecasted Water Level for Aug 22, 2014 (feet)

602.66

579.07

575

572.05

245.87

Chart Datum (feet)

601.10

577.50

572.30

569.20

243.30

Difference from chart datum (inches)

+19

+19

+32

+34

+31

Difference from average water level for Jul 22, 2014 (inches*)

+1

+1

0

-2

-5

Difference from average water level for Aug 22, 2013 (inches*)

+10

+17

+11

+5

0

Difference from long-term monthly average of Aug (inches)

+6

-2

+4

+4

+2

Difference from highest monthly average of record for Aug (inches)

-7

-35

-25

-23

-25

Year of highest recorded monthly mean

1952

1986

1986

1986

1947

Difference from lowest monthly average of record for Aug (inches)

+27

+29

+33

+37

+37

Year of lowest recorded monthly mean

2007

1964

1934

1934

1934

Projected change in levels by Sep 22, 2014 (inches)

-1

-1

-3

-4

-7

ALL DATA SHOWN IN THIS SUMMARY ARE REFERENCED TO IGLD 1985

*VALUES FOR SPECIFIC DAY ARE BASED ON 3-DAY DAILY AVERAGE AROUND SPECIFIED DATE

LONG TERM AVERAGE PERIOD OF RECORD, 1918-2013

FORECASTED INFORMATION PROVIDED BY

RECORDED DATA (1918 – present)

FOR MORE INFORMATION VISIT

Department of the Army

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Detroit District Great Lakes Homepage

Detroit District, Corps of Engineers

NOAA, Great Lakes Online

International Joint Commission

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(301) 713-9596

Great Lakes Information Network

1-888-694-8318 ext. 1

 

 

 

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.