Basic Thermal Questions

[Drenalin]

My understanding of thermals is essentially that until the ground warms up and after it cools down, thermals are dropping. As the ground warms up they rise.

Are thermals rising a function of direct sunlight, or simply daylight? I'm wondering if overcast or foggy days affect the timing of thermals starting to rise for that day.

I've always accepted that thermals will drop in the evenings, but what's the timing of that? As a rule of thumb, could I assume that at sunset thermals will start to drop? Does it happen a little earlier, a little later?

[PK_]

Your basic assumptions are correct. I haven’t actually timed it but yes very near sunrise/sunset is generally the switch. Yes overcast, fog, rain etc can delay, mitigate or switch the thermals.

[EllieTheChubb]

Your basic assumptions are correct. I haven’t actually timed it but yes very near sunrise/sunset is generally the switch. Yes overcast, fog, rain etc can delay, mitigate or switch the thermals.

it's not the sun set/rise its the setting/rising sun. when the sun is obscured by something, the mountain, tree line etc. The difference in temperature of the ground or water which retains heat longer than the air creates the thermal effect. This could happen very near sunset in flat open land or several hours before in mountainous terrain. It is all about the heat mass of the ground or water.

[Scratchman]

Thermals can also rise at night, if it warms during the night........like if a low pressure systems kicks out a block of cold air in the fall,

[oldrank]

One thing I have learned is thermals are alot more predictable than wind. By watching and noting how the thermals work at a particular stand site you can shift your kill tree and somewhat aim your thermals.

I have also noticed alot of deer traffic / trails seem to be set in thermal dump areas. This includes low end of fields, that is often discussed here. However I also noticed in small pot hole bedding the exit trails are also usually protected by a thermal dump. This make sense because it's a lower area. If you try to sit right over an exit trail the thermals are pulling right down the deer trail.

By shifting a bit off one side or the other on higher ground you can beat them. It may take a few sits to find the sweet spot.The kill tree needs to be on the correct side the deer are headed.

I also believe buck movement is triggered by the thermal switch.

[Scratchman]

One thing I have learned is thermals are alot more predictable than wind. By watching and noting how the thermals work at a particular stand site you can shift your kill tree and somewhat aim your thermals.

I have also noticed alot of deer traffic / trails seem to be set in thermal dump areas. This includes low end of fields, that is often discussed here. However I also noticed in small pot hole bedding the exit trails are also usually protected by a thermal dump. This make sense because it's a lower area. If you try to sit right over an exit trail the thermals are pulling right down the deer trail.

By shifting a bit off one side or the other on higher ground you can beat them. It may take a few sits to find the sweet spot.The kill tree needs to be on the correct side the deer are headed.

I also believe buck movement is triggered by the thermal switch.

X2 on the buck movement trigger.