Thermals vs Wind

[hokiehunter373]

I'm curious at what MPH everyone pays attention to the wind direction instead of what thermals would be doing for that time of day? For instance, I'm hunting Saturday morning, with only a 2 or 3 mph wind. I think thermals will have much more of an impact than the wind unless I get some gusts. But at what mph would you change your opinion on that? Do you already think the wind will overtake thermals at 2 or 3 mph or does it need to be above 5, 7, 10, etc.? Does it depend on the elevation change or terrain your hunting? Interested to hear everyone's thoughts.

 

[raisins]

I'm curious at what MPH everyone pays attention to the wind direction instead of what thermals would be doing for that time of day? For instance, I'm hunting Saturday morning, with only a 2 or 3 mph wind. I think thermals will have much more of an impact than the wind unless I get some gusts. But at what mph would you change your opinion on that? Do you already think the wind will overtake thermals at 2 or 3 mph or does it need to be above 5, 7, 10, etc.? Does it depend on the elevation change or terrain your hunting? Interested to hear everyone's thoughts.

The thermals and dominant wind always interact and influence each other to get what you get. It seems the amount of temperature change has an influence. For instance, if it was a cold night but the day warms up, then the upwelling thermals are more noticeable. The terrain will matter. In more rugged areas, I find the thermals more dominant. I was at the base of a mountain the last few days, and after the sun started to go down, I had a rush of thermals pouring down the mountain. Wind speed was around 5 mph all day.

This is a pretty difficult question and would lend itself to a high dollar computer model, like my buddy does for stream flow.

Without specifically tracking it, I would say at 10 mph and over that the thermals are less noticeable, at least where I hunt. The days where thermals are dominant are of course lower speed days but also the days where the wind doesn't know what it wants to do (dropped milk weed zig zags around slowly). The thermals give the wind some direction in life. Curious what others have to say. I'm guessing any rule of thumb will just be a probability guess, like with most things out there.

 

[BTaylor]

Thermal movement is vertical due to temperature change and wind is horizontal. I agree with raisins in that it really depends on where you are hunting, the type of terrain, the temperature change for the day, the weather for the day, etc.

 

[SNIPERBBB]

Thermals are important at dusk/dawn. Moreso the evening as those push air to the ground vs the morning as air moves up.The temperature change is what drives them and how rapid they are depends on how fast the temps change. Steeper the terrain the more lateral air movement which is what we're concerned with. Plan for both but wind will always win.

 

[TNbowhunter]

I don't hunt mountains or true hill country, but I've noticed thermals pulling my milkweed opposite of the predominant wind direction when the wind drops to around 5mph. The steeper the terrain and the direction of the sloped face probably influence that break-even point a good bit, but that's just a theory. Also, it's important to remember that a forecasted 10-12mph wind on the top of the hill might only be 2-3mph down in the valley, so you could see thermals "win" even on high-forecasted wind speed days. I guess what I'm getting at is that it's very situational, just like everything else in the whitetail woods...

 

[JBDaddy]

I tried keying on this concept this year. i.e. "I'll hunt spot A because the predicted wind favors it more than I think the thermals will matter" or "Hunting B today because the thermals will matter more than the low wind". I found even within a local area, forecasted wind is only a general guideline. Within a funnel, tree tunnel, clearing, slope, etc, I just find it more reliable to check my wind with milkweed every so often, or if I notice a change.

I use general wind direction for narrowing which area or side of a property I'll hunt on a given day, but when I get there it's often variable or changes over time anyway, so exactly where I set up there becomes an at-the-time decision, and I worry less about wind vs thermal ahead of time.

 

[SNIPERBBB]

I don't hunt mountains or true hill country, but I've noticed thermals pulling my milkweed opposite of the predominant wind direction when the wind drops to around 5mph. The steeper the terrain and the direction of the sloped face probably influence that break-even point a good bit, but that's just a theory. Also, it's important to remember that a forecasted 10-12mph wind on the top of the hill might only be 2-3mph down in the valley, so you could see thermals "win" even on high-forecasted wind speed days. I guess what I'm getting at is that it's very situational, just like everything else in the whitetail woods...

Unless your in a wind tunnel valley.

 

[tyson12590]

In my experience the wind usually overcomes the thermals somewhere between 5-8 mph. The problem I struggle with is that the forecasted wind speed and the actual wind speed at my stand are often very different. Many times a forecasted 10 MPH is almost non existent and a forecasted 3 MPH blows over 10. That makes it tough and that is why I try hard to find spots where I can hunt with the wind and thermal both blowing in a safe direction.

 

[BackSpasm]

I think you need to go test it with milkweed etc a lot in your area to figure it out. Sometimes I hunt an area and the thermals and predominant winds interact in crazy ways that make the spot better or worse. I make a note for the next time/ year I hunt there. There are so many variables here that influence thermals. Especially in the hill country I hunt.

 

[DroptineKrazy]

I think you need to go test it with milkweed etc a lot in your area to figure it out. Sometimes I hunt an area and the thermals and predominant winds interact in crazy ways that make the spot better or worse. I make a note for the next time/ year I hunt there. There are so many variables here that influence thermals. Especially in the hill country I hunt.

What he said.

 

[raisins]

I’ll add that the wind up a hill (or in a valley) against the dominant wind usually isn’t thermals. It’s caused by low pressure on leeward side generated by the wind cresting the hill (Bernoulli principle).

It is stronger than thermals, found all day in right location, and increases with wind speed.

 

[MattMan81]

Zach and Jeff Sturgis did a pod cast on THP about thermals. They talked a lot about Mt. Terrian and how to play it. It's a lot of info. I don't hunt Hill country. So didn't really apply to me. But I may suggest giving it a listen. It had a lot of good stuff. Might have to listen to it a few times. But I think they did a good job of trying to explain it.

 

[Robert loper]

Thermsls are gonna go to the lowest spots or the warmest spots where wet.
the sun will heat water up in the woods or swamps if it is exposed to it.
should be a bit warmer and pull air too it then usually shoot straight up. Whe it gets over the warmer water.
think if thermals or light winds like a funnel draining down into the lowest spot.
prevailing winds will bounce off obstacles and go everywhere. Notice when u are in a tree and how the wind flows around the tree and hits you. Feels like a total different direction than it really is coming from.
this in my opinion is the huge learning curve for new areas hunted. And how the deer react by travel, destination spot , and in my opinion bed

 

[ericabbott]

Great topic, I was asking myself the same question while passing time in a tree the other day. Some great responses already. As stated above there are a number of variables in play here, maybe OnX will build this into their app, they seem to be adding everything else recently lol

 

[raisins]

I tried keying on this concept this year. i.e. "I'll hunt spot A because the predicted wind favors it more than I think the thermals will matter" or "Hunting B today because the thermals will matter more than the low wind". I found even within a local area, forecasted wind is only a general guideline. Within a funnel, tree tunnel, clearing, slope, etc, I just find it more reliable to check my wind with milkweed every so often, or if I notice a change.

I use general wind direction for narrowing which area or side of a property I'll hunt on a given day, but when I get there it's often variable or changes over time anyway, so exactly where I set up there becomes an at-the-time decision, and I worry less about wind vs thermal ahead of time.

This year, I started having 4 different plans based upon whether dominant wind was N, S, E, or W for an area.

 

[hokiehunter373]

Zach and Jeff Sturgis did a pod cast on THP about thermals. They talked a lot about Mt. Terrian and how to play it. It's a lot of info. I don't hunt Hill country. So didn't really apply to me. But I may suggest giving it a listen. It had a lot of good stuff. Might have to listen to it a few times. But I think they did a good job of trying to explain it.

Yup that was a great podcast

 

[JakeFromVirginia]

I hunt national forest mountains in Virginia. Only reason I check the weather before I go would be if I thought it may rain. I check the winds as I get into the woods, and always - no matter the wind speed - play the thermals. However, if a face of a mountain is parallel with the direction of the wind, that would push the thermals in that direction (or 'cancel them out so to say'), I don't think it matters the speed as long as there is a breeze. But if the mountain face is on the backside of a ridge facing away from the wind direction (so a East facing slope on a West wind), then the thermals are predictable in my experience. And the wind blows over the ridge just fine and swirls all crazy to ruin my day as usual.

Something fun to try instead of milkweed are kids bubbles. Blow a bunch and watch in awe all the different ways the drift. Another thing to try too if you are allowed *cough* is to set off one of those smoke bombs you can find at cheap fireworks stands. They don't make noise, just colorful smoke. Thats a cool way to see how thermals and wind all react in a specific spot in the mountains.

 

[krub6b]

I hunt national forest mountains in Virginia. Only reason I check the weather before I go would be if I thought it may rain. I check the winds as I get into the woods, and always - no matter the wind speed - play the thermals. However, if a face of a mountain is parallel with the direction of the wind, that would push the thermals in that direction (or 'cancel them out so to say'), I don't think it matters the speed as long as there is a breeze. But if the mountain face is on the backside of a ridge facing away from the wind direction (so a East facing slope on a West wind), then the thermals are predictable in my experience. And the wind blows over the ridge just fine and swirls all crazy to ruin my day as usual.

Something fun to try instead of milkweed are kids bubbles. Blow a bunch and watch in awe all the different ways the drift. Another thing to try too if you are allowed *cough* is to set off one of those smoke bombs you can find at cheap fireworks stands. They don't make noise, just colorful smoke. Thats a cool way to see how thermals and wind all react in a specific spot in the mountains.

There was a wired to hunt podcast a few years back where a guy studied his family property by sitting in his tree stands with a metal coffee can that he would burn wet smoky wood in to watch the effect of thermals and wind direction on his favorite sites, especially the ones he couldn't figure out why he got busted in so much.
His take away was there are spots you simply can't hunt because of the thermals, and other places where being 10 yards in a different direction are money.

Sent from my ASUS_Z017DA using Tapatalk

 

[woodsdog2]

I'm curious at what MPH everyone pays attention to the wind direction instead of what thermals would be doing for that time of day? For instance, I'm hunting Saturday morning, with only a 2 or 3 mph wind. I think thermals will have much more of an impact than the wind unless I get some gusts. But at what mph would you change your opinion on that? Do you already think the wind will overtake thermals at 2 or 3 mph or does it need to be above 5, 7, 10, etc.? Does it depend on the elevation change or terrain your hunting? Interested to hear everyone's thoughts.

It depends on how consistent the wind is and also what other blockers may be near your location. With topography and in my experience in steeper terrain, follow the thermals.

 

[Bama_Xander]

I have generally found wind is never stable even with a direction and certain MPH. Maybe around 15-20+ you get some stability but often in the sub 10-15 mph, it flows like water and waves. Moving one way and then sucking back. Topography and the vegetation also play a role. What I have found is that I can almost never trust the wind forecasted and I need to go in nimble and adjustable. I think that's why THP is so successful, especially their ground game. They are constantly moving and adjusting. Sitting in a tree for hours is dangerous from a wind perspective. You are going to get shifts and back drafts and changing thermals throughout the hunt especially at prime time in the morning and evening.

I try to do more ground hunting to adjust to this dymanic but am often drawn back to the tree ambush.