Ice Out Largemouths and Thermal Banking

[Jim Gronaw]

I must say that I was astonished and pleased to catch a bunch of nice bass at a local lake the past few days, especially since the lake had ice just 10 days ago! But a phenomena I call 'thermal banking' likely played a key role in the quality of the catch. Here's how it plays out...

Shortly after ice out, the March sun and weather can warm the surface water 2 to 4 degrees warmer than that of even 3 to 6 feet down. With patterns in the Mid Atlantic that trend toward westerly and southwesterly winds, warmer surface water is 'pushed' and 'banked' against the northwest to northeast shorelines of lakes, reservoirs and ponds. The layer of warmer water deepens, and the entire bank region has inverted temperatures that are several degrees warmer than the rest of the lake. Even if these areas are only a few feet deep, bass will still respond by moving in and taking advantage of early season feeding activities. This only happens in the early spring progression...March...in my region. In Wisconsin, it may be May, or mid February in Alabama. By taking advantage of this yearly phenomena, you can almost guarantee that larger, adult bass will be on the prowl and active once the water hits 44 F. Here are a few picks from the last two days out of a total of 29 bass...

The big girl above struck a fast moving  1/4 oz Rat-L-Trap in less than 2 ft of water, Water temp was 46 at the shallow, wind-blown end and 42 at the deeper end of the pond.

Another fine fish from the thermal bank.

The air temp on Friday was 48, and on Saturday it jumped to 68 degrees. At the shallow, thermal bank of the pond, the areas behind me, the water temperature jumped an amazing 8 degrees in just one day! Needles to say, the fish were in there and active.

You may have to fish with the wind blowing directly in your face and make long casts. I prefer 20 lb braid and rattle baits or # 4 and #5 Mepps Aglias in silver or gold. Strikes are anything from 'crappie bumps' to solid stops. Sometimes you will feel slack in your line as a bass overtakes a bait from behind...set the hook!

Additionally, you may have to contend with algae or other weeds as your lure plows through the shallows. Clean 'em off after every cast. Good luck!

[John Sheehan]

Very excellent  report Jim .What you call "thermal banking" is a more specific example of what I've been calling ,"wind to the wall". A locating principle for sure . Thanks Jim!

http://bigbluegill.com/photo/fishing-a-rough-wind-3?context=album&a...

http://bigbluegill.com/photo/november-shore-fishin-low-water-10?con...

[Slip Sinker]

Nice looking fish Jim! we still have over 30" of ice here on the lakes... worst winter ever... single digits for lows here the past few nights. i dont see ice leaving till may.

[Jim Gronaw]

After a very cold week, I picked the warmest day to try and find bass at the local hotspot. Fish had relocated to a very small corner of the lake that was at the very northernmost spot. Strong south winds to 25 mph had roiled the banks muddy and I actuall caught all five of my fish from a spot about the size of my living room, and in 18 inches of water. Water temps were 47 degrees and later warmed up to 50. Chrome Rat-L-Traps. All fish hit amazingly close to the bank, 10-15 ft out on the very end of the retrieve, literally as I was about to lift up for another cast. Five fish, four over 18 inches. Here are the pics...

The last fish had a huge head but skinny body...should have been well over five pounds but barely made four...

Weather calls for a warming trend, so I may have to change tactics once the lake warms into the mid fiftys. Good luck!

[David, aka, "McScruff"]

Very good description of your technique.
Thanks Jim

[John Sheehan]

Fantastic,way to stay on 'em Jim!

[Jim Gronaw]

These are from 3-31 and 4-1-14...same pattern, two different lakes...

Calling for a warming trend...will change as needed.

[John Sheehan]

How big is that body of water Jim?

[Jim Gronaw]

They are ponds, John...one is two acres and the other is five. I have a couple others that are in the 5 to 7 acre size, and another that is about twenty. The thermal gig isn't doing it at the quarry because access to the wind-blown banks are not available.