Water Levels Forecast
Forecast of monthly mean lake levels for the next six months grouped as:
- high level (thers a 5% probability of exceeding this level)
- most probable level (there is a 50% probability of exceeding this level)
- low level (thers a 95% probability of exceeding this level)
Water levels are collected by CHS for the Canadian gauges and by NOS/NOAA for the American gauges. Six month forecasts of the probable range of future levels are prepared under the auspices of the International Coordinating Committee on Great Lakes Basic Hydraulic and Hydrologic Data by Environment Canada, Great Lakes-St. Lawrence Regulation Office in Cornwall and the U.S. Army Corps of Engineers, Detroit District.
Forecast Beginning 1 May 2020
Monthly Mean Water Level IGLD 1985 (metres above Chart Datum IGLD 1985)
For Exceedence Probability Shown
| LAKE SUPERIOR | Most Probable | LAC SUPÉRIEUR | ||
| MONTH | 5% | Probabilité Maximale | 95% | MOIS |
| MAY | 183.7 (0.50) | 183.66 (0.46) | 183.63 (0.43) | MAI |
| JUNE | 183.84 (0.64) | 183.74 (0.54) | 183.67 (0.47) | JUIN |
| JULY | 183.92 (0.72) | 183.79 (0.59) | 183.7 (0.50) | JUILLET |
| AUGUST | 183.95 (0.75) | 183.81 (0.61) | 183.7 (0.50) | AOÛT |
| SEPTEMBER | 183.95 (0.75) | 183.8 (0.60) | 183.67 (0.47) | SEPTEMBRE |
| OCTOBER | 183.92 (0.72) | 183.77 (0.57) | 183.62 (0.42) | OCTOBRE |
| (CHART DATUM 183.20 IGLD 1985) | (ZÉRO DES CARTES 183.2 SRIGL 1985) | |||
| LAKE HURON | Most Probable | LAC HURON | ||
| MONTH | 5% | Probabilité Maximale | 95% | MOIS |
| MAY | 177.41 (1.41) | 177.37 (1.37) | 177.34 (1.34) | MAI |
| JUNE | 177.5 (1.50) | 177.42 (1.42) | 177.34 (1.34) | JUIN |
| JULY | 177.56 (1.56) | 177.44 (1.44) | 177.31 (1.31) | JUILLET |
| AUGUST | 177.54 (1.54) | 177.4 (1.40) | 177.25 (1.25) | AOÛT |
| SEPTEMBER | 177.49 (1.49) | 177.34 (1.34) | 177.16 (1.16) | SEPTEMBRE |
| OCTOBER | 177.45 (1.45) | 177.26 (1.26) | 177.05 (1.05) | OCTOBRE |
| (CHART DATUM 176.00 IGLD 1985) | (ZÉRO DES CARTES 176.0 SRIGL 1985) | |||
| LAKE ST. CLAIR | Most Probable | LAC SAINTE-CLAIRE | ||
| MONTH | 5% | Probabilité Maximale | 95% | MOIS |
| MAY | 176 (1.60) | 175.92 (1.52) | 175.84 (1.44) | MAI |
| JUNE | 176.06 (1.66) | 175.94 (1.54) | 175.82 (1.42) | JUIN |
| JULY | 176.08 (1.68) | 175.94 (1.54) | 175.78 (1.38) | JUILLET |
| AUGUST | 176.04 (1.64) | 175.88 (1.48) | 175.7 (1.30) | AOÛT |
| SEPTEMBER | 175.96 (1.56) | 175.79 (1.39) | 175.61 (1.21) | SEPTEMBRE |
| OCTOBER | 175.88 (1.48) | 175.7 (1.30) | 175.49 (1.09) | OCTOBRE |
| (CHART DATUM 174.40 IGLD 1985) | (ZÉRO DES CARTES 174.4 SRIGL 1985) | |||
| LAKE ERIE | Most Probable | LAC ÉRIÉ | ||
| MONTH | 5% | Probabilité Maximale | 95% | MOIS |
| MAY | 175.12 (1.62) | 175.04 (1.54) | 174.98 (1.48) | MAI |
| JUNE | 175.19 (1.69) | 175.02 (1.52) | 174.9 (1.40) | JUIN |
| JULY | 175.18 (1.68) | 174.97 (1.47) | 174.82 (1.32) | JUILLET |
| AUGUST | 175.08 (1.58) | 174.9 (1.40) | 174.72 (1.22) | AOÛT |
| SEPTEMBER | 174.99 (1.49) | 174.78 (1.28) | 174.6 (1.10) | SEPTEMBRE |
| OCTOBER | 174.9 (1.40) | 174.68 (1.18) | 174.48 (0.98) | OCTOBRE |
| (CHART DATUM 173.50 IGLD 1985) | (ZÉRO DES CARTES 173.5 SRIGL 1985) | |||
| LAKE ONTARIO | Most Probable | LAC ONTARIO | ||
| MONTH | 5% | Probabilité Maximale | 95% | MOIS |
| MAY | 75.54 (1.34) | 75.44 (1.24) | 75.38 (1.18) | MAI |
| JUNE | 75.6 (1.40) | 75.4 (1.20) | 75.24 (1.04) | JUIN |
| JULY | 75.51 (1.31) | 75.29 (1.09) | 75.08 (0.88) | JUILLET |
| AUGUST | 75.32 (1.12) | 75.12 (0.92) | 74.86 (0.66) | AOÛT |
| SEPTEMBER | 75.16 (0.96) | 74.97 (0.77) | 74.69 (0.49) | SEPTEMBRE |
| OCTOBER | 75.04 (0.84) | 74.85 (0.65) | 74.56 (0.36) | OCTOBRE |
| (CHART DATUM 74.20 IGLD 1985) | (ZÉRO DES CARTES 74.2 SRIGL 1985) | |||
| MONTREAL HARBOUR | Most Probable | PORT DE MONTRÉAL | ||
| MONTH | 5% | Probabilité Maximale | 95% | MOIS |
| MAY | 8.21 (2.66) | 7.79 (2.24) | 7.36 (1.81) | MAI |
| JUNE | 7.87 (2.32) | 7.33 (1.78) | 6.87 (1.32) | JUIN |
| JULY | 7.49 (1.94) | 7.05 (1.50) | 6.55 (1.00) | JUILLET |
| AUGUST | 7.26 (1.71) | 6.85 (1.30) | 6.31 (0.76) | AOÛT |
| SEPTEMBER | 7.05 (1.50) | 6.6 (1.05) | 6.22 (0.67) | SEPTEMBRE |
| OCTOBER | 7.14 (1.59) | 6.57 (1.02) | 6.05 (0.50) | OCTOBRE |
| (CHART DATUM 5.55 IGLD 1985) | (ZÉRO DES CARTES 5.55 SRIGL 1985) | |||
- Date Modified:
- 2020-05-06