Well, fall just came rushing in this week with this cold snap. You can bet the fish know the difference.
I'd recommend putting the bass and walleye gear away this week, and busting out some musky tackle. Early fall cold snaps like this one frequently turn the fish on for a bit. Look for fish in shallow weedy areas and target them with bucktails or smaller jerkbaits. Musky will come in to patrol the shallows and feed on small gills, crappies or perch that are hagning around shallow cover. Its not uncommon to see fish as shallow as four feet when we have weather like this.
If you are gouing to bass fish, topwaters around flats are a solid bet. Buzzbaits can really produce under cold front conditions, especially when fished tight to shallow overhead cover. If you're going to flip weedclumbs or skip piers, slow way down and make sure your bait is exactly where you want it, as the fish hanging tight to this type of cover are likley to have a small strike zone right now. Later in the day, especially on sunny days, look for some active fish on the ends of rocky/sandy points or on any shallow rocks you can find.
Walleye will be moving to a night bite. Now's the time to throw large rapalas or other floating/suspending stickbaits around weed clumps just after dark. Lindy rigs will work during the day, but the better bite will be in the early evening or just after dark.
Panfish will move shallow to feed up on minnows. Look for a mixed bag of gills, crappie and perch in 4-10 feet of water. A jig tipped with live bait under a slip bobber is a good way to target these fish.
One hot bite I'd like to mention. Although the fishing has dropped off some, anglers trolling Lake Koshkonong are still picking up some whitebass. The bite on the fox river in Oshkosh and the Wolf River at Freemont is sure to get going pretty quick as well.