OT---Weather Question?

Jiles · Aug 2, 2012

I bought a piece of grown up property about three years ago. I have done a lot of tree cutting and trimming and have burnt a large amount of material.
Nearly every time I burn there is an enormus amount of smoke and it usually stays close to the ground and around me.
Over the last three days, we have had a lot of rain and I considered it safe to burn the small (Covered) brush piles.
Strange thing is--ALL the smoke went straight up and none closer then app. 20' off the ground??
There has to be a reason for this and yes I know that the wind playes a major factor but there was very little wind--I NEVER burn in windy conditions!
Might be a silly, simple question but I would like to know.

jackinok · Aug 2, 2012

probably because of the humidity,and the fact that the ground was hotter than the air temp.

Waltmo · Aug 2, 2012

barometric pressure. Low in your area things stay around, high it gets pushed out

Anonymous-0 · Aug 2, 2012

The phenomena that you saw is called an temperature inversion. Usually temperatures decrease as you move from the ground; in this case they do not. You can sometimes see smog or smoke in a valley rising up to a certain elevation and then mixing laterally. It will not penetrate this boundary layer. Usually early morning breezes, caused by heating of the earth's surface by the sun, will perforate this boundary layer and allow for mixing of the air masses.

ShadetreeRet · Aug 2, 2012

Kinda works on the same principle as ground fog, humidity high, it doesn't go anywhere, low humidity, it dissipates. I used to burn a pile of brush at night after I got home from work, you can really see how it works then. When humidity is relatively low, and a fire gets rolling good, it creates it's own "chimney", you can see just how high the heat goes when it's dark.

fixerupper · Aug 2, 2012

The high pressure comes after the storm front leaves. Depends where you live too. In the west, like Idaho, for instance it seems like the smoke almost always goes straight up. When someone is burning wheat stubble the smoke goes up and out of sight. Here in Iowa it usually stays close to the ground except if there's an unusally high pressure day. Jim

wisbaker · Aug 2, 2012

The temperature inversion, humidity and cloud cover all play into how the smoke will
act, lay out around the ground or raise away from the fire. We used to have to
consider these factors when detonating un-serviceable and hostile munitions and using
demolition charges. The same factors that effect smoke also effect blast/shock waves.
If you weren't on a licensed range with weather support popping off a smoke grenade
and watching where the smoke goes gives you an idea on how big of a shot you can
make.

onefarmer · Aug 2, 2012

What the others have said and the heat of the fire itself.

tjdub · Aug 2, 2012

One time I was driving along the Mississippi and someone across the river had a pretty good sized brush fire going in the river valley (so about 3 miles away) The valley is about 300ft deep and about 200ft up there was sharp air temperature boundary. The smoke was going staight up from the fire and then BAM it just stopped and made a thin layer of smoke that went up and down the valley at least 10 miles in each direction and never got any higher. It was completely calm and clear that day so it was really a sight. I stopped and tried and tried to get a good picture of it, but I just couldn't get a photo to do it justice. My wife thought I was nuts, but I guess I just find some really boring things interesting

Jiles · Aug 2, 2012

(quoted from post at 18:33:53 08/02/12) One time I was driving along the Mississippi and someone across the river had a pretty good sized brush fire going in the river valley (so about 3 miles away) The valley is about 300ft deep and about 200ft up there was sharp air temperature boundary. The smoke was going staight up from the fire and then BAM it just stopped and made a thin layer of smoke that went up and down the valley at least 10 miles in each direction and never got any higher. It was completely calm and clear that day so it was really a sight. I stopped and tried and tried to get a good picture of it, but I just couldn't get a photo to do it justice. My wife thought I was nuts, but I guess I just find some really boring things interesting

Sounds like I am a lot like you. Many times I see things other people overlook and I like to know how things work

Harold H · Aug 2, 2012

Both the wind and the barometric pressure effect where the smoke goes. In 2004 we were flying to a convention in California. That was the year of giant forest fires over the Arizona area. When we got near Winslow, our path was blocked by dense smoke in both directions for about eithty or more miles across our path. We tried to go around it to the north and decided that that was impossable so we decided to go over it. As we climbed along side it we finally reasched the top right at 14,000 feet. The top was just as smooth as a calm ocean and extended as far as you could see without a ripple. We flew probably twenty five miles across it then dropped back down. The winds and barometric pressure shaped the smoke like it was in a contained form.

Harold H

OT---Weather Question?

Jiles

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jackinok

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Waltmo

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Anonymous-0

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ShadetreeRet

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fixerupper

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wisbaker

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onefarmer

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tjdub

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Jiles

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Harold H

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