Watch Lake Erie slowly freeze over

 This is mostly turn-over, where the colder water sinks when it hits maximum density at 4C.  

At 3C, the water becomes less dense and quickly forms ice, since there is no more water movement.

ps 

It's ironic that if we could see through Lake Erie on the Canadian side, we would see tons of methane pipes, connecting wells, and they leak all the time when they are broken by ice ridges.  You can't see that, and you can't know about that.  But the methane doesn't do anything, anyway.

ps. we can now measure with satellite, the co2, methane, and earth's radiating heat.  If they were correct, you would see the co2 and methane damping the heat release, the whole clange thing is based on that.  Easy to measure now, but it won't be.