The currents of Lakes Michigan and Huron / John C. Ayers.

8

Point to Oscoda. It still travelled south along the shore past Tawas Point and
dipped into Saginaw Bay. The eddy that normally lay off the mouth of the bay
was almost against shore at Oscoda. The flow-through current emerged from
Saginaw Bay along the south shore of the bay mouth, but instead of going northeastward to mid-lake it passed in a southeasterly direction almost to the
Ontario shore from whence it moved southwest to the St. Clair River.
The mid-lake eddy was almost non-existent on 27 July. All that remained
of it was a circular arrangement of weak currents off Macpherson Point. A
weak eastward branch of the flow-through current left that current at about 44~
10' and passed northeastward along the side of the remnant of the mid-lake
eddy. Another eastward branch of the flow-through current left the east side
of that current in latitude 44 45' and crossed almost to the Saugeen Peninsula.
This is interpreted as being the beginning of the re-establishment of a normal
mid-lake eddy as the result of the west and northwest winds of the days just
prior to the survey.
In the southern end of the lake the winds (Table 2) had been from the north
and northeast for six days prior to the survey of 27 July. The southward and
westward displacement (of currents) resulting from these winds causing the
flow-through current to slant southeastward across the lake instead of going
northeast to mid-lake then south and southwest to reach the Michigan shore
below Harbor Beach. The counterclockwise eddy which "normally" was situated
off Goderich was, on the 27th, at Grand Bend.
Lake Huron, Winds South of Normal
On 25 August 1954 Lake Huron was surveyed after the winds over the central and southern parts of the lake had been from the south and east for four
of the preceding seven days (Table 2). Chart 14 presents the current pattern
in the lake on 25 August. Again, winds in the Straits region were from essentially the normal west northwest, and again the currents in the upper portion
of the lake were not materially modified from the normal condition.
In the central portion of the lake the currents were displaced to the east
and north. The flow-through current was deflected to the eastward at Presque
Isle and flowed eastward and northeastward to Manitoulin Island. In doing so,
it passed around the south end of the mid-lake eddy which was displaced northward and was centered about at the Duck Islands.
Currents directed off the shore arose along the Michigan coast from Oscoda
to Thunder Bay. About half of these turned eastward above Thunder Bay and
crossed to Cape Hurd, from there they went northwest along the shore of Manitoulin Island and up the east side of the mid-lake eddy. The other half turned
eastward above Thunder Bay but then went south almost to Pointe aux Barques.
Here they curved northeastward and crossed into the east-central part of the
lake off Macpherson Point. From there a part went northeast along the Saugeen
(Bruce) Peninsula and a part flowed south along the center of the lake. The
clockwise eddy normally situated at the mouth of Saginaw Bay was displaced to
the north and east and lay about a third of the way across the lake. Inflow
into Saginaw Bay appeared to be up the center of the bay mouth and outflow
from the bay was along its south shore.
In the southern end of the lake, northeast currents rose from the shore
between Lexington and Harbor Beach. These in part turned south in mid-lake
east of Pointe aux Barques and in part joined the cross-lake current from
Saginaw Bay and went to the offing of Macpherson Point before returning south