2020-Mar-09
March 8 Water Levels Report
Water levels continue to be well above average and near or above record high levels. From a month ago the water levels on Lakes Superior, Michigan-Huron, and St Clair are all down by 3 inches, Erie is up 1 inch and Ontario is unchanged. Lakes Superior, Michigan-Huron, St. Clair, Erie & Ontario are 1, 14, 10, 12 & 7 inches higher respectively than they were at this time last year, and 14, 35, 35, 33 & 18 inches, respectively above their long term February average. Lakes Michigan-Huron, and Erie are 3 and 2 inches higher, respectively, than their previous record highs for February. In a month’s time, the level of Lake Superior is expected to be unchanged, and Lakes Michigan Huron, St. Clair, Erie & Ontario are all expected to rise by 2 – 4 inches.
Outflows from Lake Superior into the St. Mary’s River and Lake Michigan-Huron’s outflow into the St. Clair River are predicted to be above average for this month. Lake St. Clair’s outflow through the Detroit River and Lake Erie’s outflow through the Niagara River are also forecasted to be above average in this month. In addition, Lake Ontario’s outflow through the St. Lawrence River is projected to be above average for this month.
High water levels and potentially record high water levels are expected to persist for at least the next six months, so flood prone areas are expected to remain vulnerable. Water levels and flows in the connecting channels can be significantly impacted by ice during the winter months.
With regard to the forecast graph below, it should be noted that USACE predicts that the most likely outcome is that levels will exceed last year’s high in July by 5.3”. It looks as if there will be less ice cover and therefore more evaporation than there was last winter. However, if precipitation is much the same as last year over the next 4 months, then water levels will likely be nearer the top end of the predicted range (orange area in graph below) – which shows 13” above last year’s high in July. Currently precipitation levels are lower, but the key months for determining how much water levels will rise (or fall) will be April to June.
Please note that the green, blue and purple lines in the USCE forecast graph show what happened with water level changes from month to month in each of the years 2019, 1996 and 2017 – they do not represent actual water levels in those years.
The are no clear recent satellite image, but partial images show that the North Channel has a little more open water than last week, and there is no material change in ice cover along the east shore and offshore areas from last week – i.e. very low ice cover out in the Bay but shoreline ice intact.