Paul Nelson: Predicted rain could hasten fall cooling of area lakes
How fast the lakes go through the progress of cooling in the fall depends largely on how warm it is during the day and how cold it gets at night.
Anglers could take out a calculator and average the daily highs and lows for a week and come pretty close to what the surface water temperatures will be in the lakes.
Factors that tend to speed the process include significant amounts of rain (especially at night) and strong winds from multiple directions.
Strong shifting winds help mix the surface water into the water further down in the water column. This evens out the water temperatures above the thermocline and helps break down the thermocline in the deep lakes.
Wind shifts usually accompany strong cold fronts like the one forecast to come through the Bemidji area starting today through Saturday, with up to an inch of rain possible.
Surface water temperatures in the local lakes have been holding in the low 60s, but they could plummet if the amount of rain in the forecast turns out to be correct.
A slow cool down that takes a couple of weeks for the lakes to go between 60 and 50 degrees would be ideal for fishing, but we have to take what we get when it comes to the weather.
Fish migrations usually peak as water temperatures reach the mid 50s, whether the fish are moving a short distance across a small lake or traveling many miles in one of the Great Lakes or some of the larger lakes in Canada and the U.S., to reach their early winter locations.
Muskies, walleyes, big pike, bass and even crappies are usually on the move as the water temperatures reach the mid 50s in the fall.
A good example of a fish migration can be seen when walleyes come from all over the southern portion of Lake of the Woods to feed on emerald shiners in the Rainy River in the fall.
Many large lakes have more than one migration of walleyes and other species in the fall. For example, “green-back” walleyes out of Lake Winnipeg migrate into both the Red River of the North and the Winnipeg River in the fall to feed on shiners and other baitfish.
There are many other river systems connected to large lakes or chains of lakes that have runs of big walleyes in the fall, including the English River, the Illinois River, the Saint Louis River, the Saskatchewan River and the Missouri River.
Anglers often know from past years where the fish are heading in the fall so they are able to make educated guesses on the path the fish will take. Anglers then can concentrate on potential bottle necks that are located along the most predictable routes.
If anglers can locate high traffic areas for species like walleyes and muskies, they can dramatically increase their chances for success during the time period when the fish are on the move.
Lake of the Woods, Rainy Lake, the St. Louis River and the lower Mississippi are all within reasonable driving distance from the Bemidji area.
Local anglers can also consider traveling to the Missouri River near Bismarck or one of the reservoirs along the Missouri River in North Dakota, South Dakota and even Fort Peck in Montana.
Devils Lake and the Glacier Lakes of South Dakota are other possible location for anglers wanting to take a fall fishing vacation to another area within reasonable driving distance.
Anglers preferring to stay closer to home should have some good fishing when the weather stabilizes. Most species of fish are active in the fall, so once anglers locate the fish they should be willing to bite.
Leech Lake and Winnibigoshish have both turned on for walleyes on the days with some wind along shoreline structure in 5 to 9 feet of water. Both the rocks and the deep weed edges have been holding some fish.
The deep lakes should also be turning on soon for walleyes and other species, especially on the days with less wind when anglers are able to slow their boats and hold over the fish more easily.
PAUL A. NELSON runs the Bemidji Area Lakes Guide Service. He can be contacted at firstname.lastname@example.org