Thermals around water

[ThumbsMcGee]

I’m having a hard time remembering how thermals work around bodies of water, and google isn’t being helpful right now.

Say you have a creek or pond. During the evening do thermals flow away from the water due to the drop in atmosphere temps and the sustained temps of the water from the sun? Or does the warm air around the water pull in colder air creating thermals towards the water?

 

[Mengle]

Not sure if this helps or not, but in my experience, if the sun is beating down on a pond and I am close in the shade in a tree- the milkweed goes down to the pond and when it gets close to the edge of the pond it starts to get sucked up in the air.

 

[NW_Arkansas22]

Depends on several factors. The temperature of the water, size of the creek/pond, and if the water is moving/flowing.

 

[Jwiggins762]

I haven't experienced it yet myself but everything ive heard is in the evening it sucks towards the water and the morning it pushes it away. If you have high winds it probably doesn't matter. Cant wait to see how thermals work though. FUN FUN

 

[NW_Arkansas22]

I haven't experienced it yet myself but everything ive heard is in the evening it sucks towards the water and the morning it pushes it away. If you have high winds it probably doesn't matter. Cant wait to see how thermals work though. FUN FUN

Ground temp changes much faster compared to water temp. If the water temp is warmer than ground temp, nothing will be sucked towards the water. Like I mentioned before, it depends on several factors and what type of water source you're hunting.

 

[EricS]

Hunting close to water bodies can get confusing. I wish I had an answer for this myself. I know it depends on water temperature, ground temperature, air temperature, wind direction, size of waterbody, and whether it’s open or wooded.
What I do know for sure is if the wind is light and it’s blowing the perfect direction for me to hunt a spot it will change to variable and then steadily blow in the wrong direction in those magic last 20 minutes of daylight. For those reasons I only hunt by big ponds or lakes when there is a good steady 10+ mph wind or I wear scentlok. Morning hunts will do the same except it’s usually about an hour after daylight before the wind gets shifty. Small wooded creeks and rivers don’t seem to effect them as much but keep in mind that long straight stretches of creek will cause wind to do funny things as well as creeks are usually at a lower elevation than the area around them.

 

[CptFrank]

Ground temp changes much faster compared to water temp. If the water temp is warmer than ground temp, nothing will be sucked towards the water. Like I mentioned before, it depends on several factors and what type of water source you're hunting.

When i was in college i had a job on a parasail boat so i had quite a few lessons in thermals and how they relate to large bodies of water

In the spring, the ocean water would be cold so the air would rise over the land causing ocean air to take its place resulting in an "on-shore" breeze.
Later in the year when there were cool days but the water was warmer, ocean air would rise and be replaced by air from the beach causing an "off-shore breeze"

If i was hunting next to a large body of water in the fall i would expect the wind to trend towards the water on still days (and predominantly off-shore in the spring) since the water will be warmer than the air.
A smaller body of water will have the same affect but will change temperature quicker. Therefore if it was hot for a few days but then a cold front came through, i would expect thermals to go towards the water than up. If the temps just rose after a few cold days expect any deviation to be away from the pond.

If the body of water was flowing, you may experience similar reactions to the examples above, but it may also cause a downstream air flow if the creek is big enough and flows hard enough.

Obviously this is just a rule of thumb but in my experience it holds true. Hope this helps!

 

[NW_Arkansas22]

If i was hunting next to a large body of water in the fall i would expect the wind to trend towards the water on still days (and predominantly off-shore in the spring) since the water will be warmer than the air.
A smaller body of water will have the same affect but will change temperature quicker. Therefore if it was hot for a few days but then a cold front came through, i would expect thermals to go towards the water than up. If the temps just rose after a few cold days expect any deviation to be away from the pond.

If the body of water was flowing, you may experience similar reactions to the examples above, but it may also cause a downstream air flow if the creek is big enough and flows hard enough.

Obviously this is just a rule of thumb but in my experience it holds true. Hope this helps!

That's a really good example CptFrank and an easy illustration to follow. I was more so referring to small ponds/creeks where the thermal pull would be much less significant. I have absolutely no experience hunting next to large bodies of water or large rivers.

 

[rxforsaddlehunt]

That's a really good example CptFrank and an easy illustration to follow. I was more so referring to small ponds/creeks where the thermal pull would be much less significant. I have absolutely no experience hunting next to large bodies of water or large rivers.

Great topic, following! I was watching Dan Infalts farmland bedding video and it showed him throwing milkweed towards a pond as it got near dusk and it was drawn right to the pond and then up as it got over the pond as CptFrank described. Interesting info.

 

[NW_Arkansas22]

Great topic, following! I was watching Dan Infalts farmland bedding video and it showed him throwing milkweed towards a pond as it got near dusk and it was drawn right to the pond and then up as it got over the pond as CptFrank described. Interesting info.

I know exactly what video you're talking about....it's definitely subjective based on the terrain your hunting. The area I hunt is hill country where the thermal pull of the valley & drainage outweigh the thermal pull of a cattle pond. I should have asked what terrain he was hunting before commenting lol

 

[CptFrank]

I know exactly what video you're talking about....it's definitely subjective based on the terrain your hunting. The area I hunt is hill country where the thermal pull of the valley & drainage outweigh the thermal pull of a cattle pond. I should have asked what terrain he was hunting before commenting lol

Hills are the part of thermals i can never remember since I've been a flat lander my whole life haha.

 

[NW_Arkansas22]

Hills are the part of thermals i can never remember since I've been a flat lander my whole life haha.

In the area I hunt, the hills are steep enough to create shade in the valley's starting around 3 - 4 o'clock in the afternoon so that cool air is rising all day. As soon as the sun goes down or the side of the ridge you're hunting gets shaded, the colder air starts to settle into the lower parts of the valley's. Depending on the time of year, you can feel the thermal pull downward. Crazy how it works...

 

[CptFrank]

In the area I hunt, the hills are steep enough to create shade in the valley's starting around 3 - 4 o'clock in the afternoon so that cool air is rising all day. As soon as the sun goes down or the side of the ridge you're hunting gets shaded, the colder air starts to settle into the lower parts of the valley's. Depending on the time of year, you can feel the thermal pull downward. Crazy how it works...

What confuses me somewhat is why it is so morning or afternoon dependent. Sunny side = rising, shady side = falling makes sense to me but from what i hear other say that there are more rising thermals in the morning and falling thermals in the afternoon.

For example, what are the thermals doing on the shady side in the morning? My guess would be falling or the wind would be blowing towards the sunny side. But if thats the case would it blow over the ridge or across the valley to the next slope?
In the afternoon i understand falling thermals on the shady side, so is this air traveling down into the valley to rise up the sunny side?

 

[NATHAN]

Hunting Beast did a short video about it.

 

[NW_Arkansas22]

What confuses me somewhat is why it is so morning or afternoon dependent. Sunny side = rising, shady side = falling makes sense to me but from what i hear other say that there are more rising thermals in the morning and falling thermals in the afternoon.

For example, what are the thermals doing on the shady side in the morning? My guess would be falling or the wind would be blowing towards the sunny side.

IMO it definitely depends on the wind and how cold/hot it was the night before. But to answer your question I believe your scent is falling....whether this is from thermals pulling or not I'm not sure.

But if thats the case would it blow over the ridge or across the valley to the next slope?

You shouldn't have to worry about it blowing to the next ridge/slope because that would be the windward side of the ridge and deer shouldn't be traveling there.

In the afternoon i understand falling thermals on the shady side, so is this air traveling down into the valley to rise up the sunny side?


If there were two paralleling ridges running north and south.....yes, theoretically the falling thermal on the shady side (East side) of one ridge will fall and be pulled upward towards the sunny side (West side) of the other ridge. I try to focus on the particular ridge I am hunting because that's the ridge I am anticipating deer movement. If I spook deer on an adjacent ridge, I've lost nothing.

 

[Recurveaholic]

Do like alot of these guys do and get some milkweed and test it for yourself!! You will be amazed!!!! It is definitely worth the effort, it's awesome!

 

[ThumbsMcGee]

Thanks all for the replies. It’s been insightful, especially when y’all mentioned the short video on YouTube. Here it is:

Sent from my iPhone using Tapatalk

 

[CptFrank]

What confuses me somewhat is why it is so morning or afternoon dependent. Sunny side = rising, shady side = falling makes sense to me but from what i hear other say that there are more rising thermals in the morning and falling thermals in the afternoon.

For example, what are the thermals doing on the shady side in the morning? My guess would be falling or the wind would be blowing towards the sunny side.

IMO it definitely depends on the wind and how cold/hot it was the night before. But to answer your question I believe your scent is falling....whether this is from thermals pulling or not I'm not sure.

But if thats the case would it blow over the ridge or across the valley to the next slope?

You shouldn't have to worry about it blowing to the next ridge/slope because that would be the windward side of the ridge and deer shouldn't be traveling there.

In the afternoon i understand falling thermals on the shady side, so is this air traveling down into the valley to rise up the sunny side?


If there were two paralleling ridges running north and south.....yes, theoretically the falling thermal on the shady side (East side) of one ridge will fall and be pulled upward towards the sunny side (West side) of the other ridge. I try to focus on the particular ridge I am hunting because that's the ridge I am anticipating deer movement. If I spook deer on an adjacent ridge, I've lost nothing.

The two things you said that make sense to me that i think i was missing before are 1) Deer wont be on the windward side and 2) The next ridge doesnt matter, (presumably because deer are less likely go into one bottom then up the other side? I guess they either stay on their ridge or find an intersection/funnel to cross?) If i'm right about what you are saying, its reasonable to only expect deer movement more or less parallel to the ridge making it possible to stay above the deer with a rising thermal and below them with a falling one.

 

[CptFrank]

Do like alot of these guys do and get some milkweed and test it for yourself!! You will be amazed!!!! It is definitely worth the effort, it's awesome!

Yeah i agree that the first hand experience is the best way to learn but i never hunt or even spend much time in hill country so my question was more out of curiosity than anything else.

 

[NW_Arkansas22]

The two things you said that make sense to me that i think i was missing before are 1) Deer wont be on the windward side and 2) The next ridge doesnt matter, (presumably because deer are less likely go into one bottom then up the other side? I guess they either stay on their ridge or find an intersection/funnel to cross?) If i'm right about what you are saying, its reasonable to only expect deer movement more or less parallel to the ridge making it possible to stay above the deer with a rising thermal and below them with a falling one.

I've seen it happen a couple of times but a deer will rarely walk the windward side, drop to the bottom, and come up the other side of the next ridge. I could see this happening if there was a drastic 180 degree wind change. The only two times I've personally seen this was a buck covering ground in rut and a doe who crossed my ground scent and was spooked.

The hill country I hunt has zero ag......no ag for 50+ miles so the deer rely on acorns and natural browse. The deer are pressured pretty good so outside of the rut, the deer don't move much at all before sunset and will have plenty of food to browse on all around them. They stand up and stage in the general area they are bedding and wait for dark. Knowing that, I obviously try to hunt the ridge I think the deer are bedding on. So to your point, yes I am hunting the expected parallel movement on the ridge I am hunting.