Thermals?

[wannabeelkhntr]

Greetings MM folks. I have been enjoying this site as a spectator for a year or two, but finally decided to participate. I am going on a CO archery elk hunt in sept. For whatever reason, I can never get a grasp on the concept of mountain thermals and what they do and at what times of day they go up or down. When they move, do they create a breeze that a person can feel, or does the air mass create more of a drift effect? The wind in the mtns is soooooo unpredictable and I have probably loust up more opportunities that I didn't even know existed because the game caught wind of me before I was anywhere in the neighborhood.

Thanks for your input.

GR

 

[timwlarsen]

Easy way to remember is that cold moves to warm unless there is atmospheric wind (then it just depends on your surrounding- if it will swirl or not). In the morning, the sun will hit the upper reaches first - warming them - pulling the colder air to it. Once the lower reaches warm for the day they will reach a flat point- around late morning. Then they reverse as lower will warm more than higher elevations.
Normally the higher you hike the cooler it gets durning the day (a few degrees per 1000 feet). They will continue to fall until temps flatten again.

 

[Edpre]

I always remember:

#1 If there's a wind strong enough for me to notice, without doubt, that's the way the wind is blowing and carrying my scent.

#2 In lack of wind, hunt up to them when there's no sun, hunt down to them when there is sun.

#3 Plan ahead for #2. If it's 6:00 am now and I won't reach 'em till 10:00 am, plan #2 for what you predict it'll be like when you're within smelling distance of 'em, around 9:00 am in my example.

Warm air rises, cool air falls, sun heats the air by heating the ground/trees/rocks/etc. And yes, sometimes when everything is just right, you can actually feel thermals working.

 

[megalomaniac]

As the above posters have said...

Playing the thermals is CRITICAL to harvesting an elk with a bow. Also remember prevailing winds may override the thermals.

Stay below the elk before sunup.

After the sun rises, the thermals reverse and scent travels up.

The cow I shot with my bow last year walked up to within 3 feet of me because I had a strong thermal in my favor.

It won't take but one morning on top of the mountain to have it figured out.

 

[txhunter58]

Warm air rises. Cool air falls. It is as simple as that.

As stated earlier, the sun controls thermals. If the sun is shining WHERE YOU ARE, the air will travel uphill. When the sun is not shining on where you are, the air will travel downhill.

That means the they shift both morning and evening during prime time (around sunrise and sunset) making it hard to hunt only one direction. If possible, try to sidehill it toward the elk when you get close.

txhunter58

venor, ergo sum (I hunt, therefore I am)

 

[wannabeelkhntr]

Good stuff guys. See, now this info will be on the site. I can print it off and if I lose the print out I will be able to look back into the archives. I appreciate your input it really good and it appears that you all have a really good grasp of thermals.

Now, I have one last question. If you plan on backpacking in, how close should a person camp to the area you expect to hunt? I should tell you that we plan on at least glassing as much of the area from a distance to get an idea if there are elk in the area or what they may be doing at the time before we spike our camp. I have been advised that I should not spike a camp closer that I expect to hunt.

 

[Edpre]

I think it depends on what exactly you envision as "camp". If it all fits into your pack, has little to no odor, no stinky liquid fuel, no fire, a bivy sac on the ground, no grilled liverwurst and onion sandwhiches, and no evening bull-sessions that'll get louder than a bit above a whisper, then I think you can be pretty close to where they live, say a mile or less.
If camp is a big tent, tarp, gas grill, fire pit, pickled eggs and some medicinal beer, then I'd shoot for 2 mile minimum from where you plan on actually hunting them.
It's all pretty relative to the exact situation, topography, and even your personal "camp" habits. Just always be on the safe side, and remember that if you're too close to their home, you'll bugger them, and if you're too far you'll spend valuable hunt time and energy getting to and from them, instead of hunting 'em.

 

[3blade]

not to be a smart alec or anything but the Law of Thermal Dynamics states. "Hot goes to cold". The hot air rises because at 30,000' its -35. Its trying to heat that air.

The sun interacts with terrain and atmosphere. The lower the elevation the thicker the atmosphere so it has a tendency to warm quicker. Couple this with the terrain, its easier to heat rock and dirt than trees and plant life and lower elevations get much hotter than high.

any way, before the sun comes up the cold air falls so stay below the game. As the earth warms from the lower elevations the warm air begins to rise and will do so throughout the day. Once the sun pretty much disappears, or shortly before in shaded areas, or is low on the horizon, the cold air will begin to fall because the warmth created by the suns interaction with air and earth is no longer rising and heating that cold air at 30,000'.

 

[wannabeelkhntr]

Basically, air heads down as the sun comes up then shifts up sometime later in the morning. Then the air rises as the sun falls.... That's what I understand. However, a prevailing wind will usually overtake thermals in most instances and since you can feel and check the wind using various methods, one can also check the thermals in the same manner in the absence of a prevailing wind. Thus keep a good crosswind or wind in the face at all cost. Thermals are helpful to know when planning an attack.

Thanks,
GR