Cold Front Bass
June 02, 2015
Fishing line climbs off the water and hangs overhead. Static electricity makes potent shocks emanate from graphite rods, reel seats, bolts, and every conductor on board.
Those are second and third wake-up calls. You should already be out of there. But the fishing's fantastic. Bass are almost jumping in the boat. In about 10 to 20 minutes the sky will lift, winds will pick up, the bite will disappear. The key question, of course, is: Why did you risk your skin for a bunch of fish? But anglers everywhere wonder, "Why did they stop biting? Fact is, nobody knows why bass and other species stop biting after a cold front passes, or why they often remain less active (especially big bass) for a few days afterward. But we have theories.
Cold Front Mechanics
Cold fronts are caused by moving masses of cold, dense air, which forces warmer air upward. Turbulence mixed with rising vapor can cause storms to form along the leading edge of the front. Cold fronts move in to two times faster than warm fronts and generally produce more dramatic changes in weather.
Crazy fluctuations in air pressure seem to affect bass most. Pressure decreases steadily as the front approaches, hits a low point as the front passes, then rises as dense, cold air settles in. Bass guides and pros have reported for years that, as a front approaches, bass move shallow and become highly active. If true (and it sure seems to be), it dispels the theory that bass are moving to equalize swim-bladder pressure. If so, they would move down in the face of decreasing pressure.
Conversely, according to that theory, cold front bass should move up as pressure increases after the front passes. They don't. In most cases they move deeper. Post-frontal conditions are also characterized by bluebird skies. Maybe bass try to avoid excess radiation and brightness? Perhaps. But nix the swim-bladder stabilization theory.
Another bit of conjecture: Zooplankton rise in low pressure, baitfish follow, and bass feed accordingly. When pressure declines, zooplankton drop into cover, baitfish stop feeding, followed by bass. But that doesn't explain why bass remain less active for days afterward without incorporating other theories. If plankton stay in cover for days, so what? Bass could feed on crayfish, which don't focus on plankton at all. But they don't. They remain less active.
Some say bass are simply gorging then resting. Well, duh. They do that during stable weather, then put the feedbag back on the next day. Post-frontal bass don't do that. Face it. We can't address the physiological responses to cold fronts fish exhibit because we don't understand them yet. What we do understand is fishing. We can continue to catch bass after fronts if we adhere strictly to the rules. After a front moves through, and for days afterward in most cases, the strike window of larger bass (over 4 pounds) shrinks to an area mere inches in diameter.
They won't chase, they won't even move unless you put a bait right on their nose. Even then it might take 5, 6, or more presentations on the same spot to tempt a bite. In response, baits must be moved incrementally. It's slow, it's tedious, and it's impossible unless you have a good idea exactly where they live.
Targeting a river for smallmouth bass after a cold front is brilliant. Smallmouths in rivers may even continue to strike topwaters and cranks, but it's more likely you need to slow down and swim plastic grubs or resort to drop-shot rigging. They might position less aggressively as well. Instead of facing into current in classic feeding positions at the head of a pool or eddy, they may tuck in behind current breaks or position between the center and tail-out of a pool.
In natural lakes and reservoirs, smallmouth bass turn off, but follow a relatively predictable routine. After feeding heavily in depths of 2 to 12 feet, they drop down as the front hits and pressure increases. They tend to tuck in tight on sharp drops and ledges along whatever structure they were using. It's typical to find them at the base of the sharpest drop-off around reefs, points, humps, and channels in 12 to 25 feet. And they refuse to eat unless you politely insist.
In other words, you have to be pretty certain you're on fish. Underwater cameras help because fish can be hard to find on sonar. Bass eventually respond to slow, persistent presentations, however. Cast back to key spots repeatedly. Drop-shot rigging is a potent weapon in these conditions. Gently twitching a bait in place, and leaving it in place for long periods of time, finally entices bites — if you're fishing right in their face. The problem with a drop-shot rig is unwanted movement. Your pulse pounding through your fingers can make a dangling plastic dance. I often find that a football head dressed with a 3-inch craw or spider grub works better when the bait needs to remain perfectly still at rest.
Joe Balog, Great Lakes smallmouth ace, has to fish tournaments whether a front passes or not. He recommends slowing down after a front. "The mood of a smallmouth changes under overcast, stormy conditions," he notes. "Smallmouths and largemouths both become negative. My answer has been a drop-shot rig. I won a BFL event in 2009 on Lake St. Clair in a terrible summer storm. The fish were murdering crankbaits right up until the front came through. As soon as the rain hit, I could only get bit on drop-shots fished slowly.
"In deeper water, like Lake Erie, effects of fronts are less predictable," he adds. "I prefer sun, but I've taken some monster stringers in rain and sudden cold. I always go to a dark bait in those conditions, like a dark melon tube. I think they see it better. Shallow fish are unpredictable at best. Deep bass seem less affected. From 25 feet on down, you catch bigger fish more consistently after fronts pass. I also rely on baits infused with scent, like Berkley Gulp! or Trigger X, and I grind them out with a drop-shot rig. Some baits won't work if I don't add scent."
After cold fronts pass, I commonly find smallmouths tucked into the base of sharp drops along the deep edge of whatever structure they were using before the front hit. In shallow lakes, these spots might be 10 to 14 feet deep, right along the edge of the last boulders or hard bottom defining the base of a reef where it blends into softer substrates. In deep lakes and reservoirs, it might be 15 to 40 feet deep (release fish immediately when they're hooked deeper than 20 feet), often on a ledge, shelf, or boulder line along the face of a bluff.
Try to hold the lure still on a taught line for long periods. Waves, current, and boat movement move the line anyway, but that's okay. A scented 3-inch Yamamoto Craw or Hula Grub on a 1/8- to 3/8-ounce football head is a favorite. Another is a Gulp! Minnow or Jackall Cross Tail Shad on a drop-shot rig. Just the attempt to hold small baits motionless in waves imparts a subtle range of tension that rolls, wiggles, lifts, and drops the bait. In calm water, drop-shot rigs work even better, while jigs must be dragged slowly with long pauses.
Small fish typically dominate the catch when fishing largemouths after a summertime cold front, largely because we fail to change tactics. Big bucketmouths seem philosophically opposed to chasing anything — even a slow swim jig — after a front. Deadsticking softbaits can be effective for big largemouths in the first 24 hours after a front passes. But, again, knowing where they live is critical.
Go back where you were catching them previously and concentrate on the thickest, deepest cover. Fish slower, and make repeated casts to high-percentage spots. Largemouths bury under the thickest canopies, as if trying to keep every photon of that bluebird sunlight off their bodies. Weights and jigs must penetrate that cover.
Most options can be rigged on a belly-weighted hook for deadsticking. Adjustable weights are ideal because shifting weights forward on the hook creates a nose-diving effect. The new Sebile Soft-Weight System, with small tungsten adjustable weights is great. Leave the bait on bottom for minutes at a time. Continue to work thick cover at a painstaking pace.
In northern natural lakes, I target the same humps, weedlines, and cover that's been producing best. But after barometric pressure begins to rise, largemouths no longer hold on top or in classic ambush positions. They bury themselves under weed and wood cover. A heavy, weedless, drop-shot rig often works best, using weights of 1 ounce or more. This rig can plummet through dense cover and sit there, enticing a strike, as long as you care to leave it in place. Scent makes a big difference for largemouths as well, after a front. I add Dr Juice Bass Scent to all softbaits. Use whatever product you have most confidence in.
Big bass don't always drop into deep water after a front. They might be in 6 to 8 feet of water or less if cover is thick. Smallmouths feeding in 6 feet of water often position in depths of 10 to 12 feet after a front, tight to the base of a reef, hump, or point. Spend most of your time fishing dense cover on inside turns in the weedline near sharp breaks, or the base of the break on rocky structure, and bass eventually reveal themselves — but only if you insist. Politely.
Matt, Straw, Brainerd, Minnesota, is a smallmouth guru and In-Fisherman Field Editor.