I have got pretty good at reading the wind when shooting on relatively flat ground like we have around here in Dallas, but how do you guys make your wind calls for a shot from one wall of a canyon to another when you have no objects to reference in the middle of the canyon in the open air?

Try to look at something that is moving close to you like a grass top or tree top on the side your on or do the " throw the dust in the air trick" and do your best to pick something up in your scope that may be moving on the other side and try to determine if the wind is blowing the same direction on both sides. It is difficult at times for sure. If you can't see anything on the other side that the wind is moving base the shot on the wind you know which is the wind where you are standing.

I have passed on some fairly easy shots because of that unknown. Often you will have several thermals, than add winds in different directions. I try to gauge by the winds on the other side, that is where the deflection will show the most IMO. Time of day can also affect bullet trajectory with air heating (afternoon) and cooling in the evening.

If it is real breezy, I will try to use that to my advantage and get closer (like in Elk hunting), if it is not possible, I will gauge the situation and decide if the shot is worth the risk.

Longest shot I have made on a Bull was 527 yards across and up, but it was fairly light winds and a decent (could feel it) evening downdraft. I new my basic drop at that range, so only had to hold into the breeze about 20". Thank goodness I had 3 buddies with me, Bull fell and we got him out fairly quick.

There are charts you can get, and I believe even apps for a smart phone now, to help calculate windage.

I will always opt to move closer if given the opportunity.

I likes ta reach in ta me arsenal bag. pull out a smoke grenade, load up the .203 & fire a round.

You need to practice reading the mirage. Get the book by David Tubb or Nancy Tompkins. I think they explain mirage. Bottom line is that you are going to have to sit at a range with someone who knows how to read mirage and compare wind estimates, until you are confident. With side parallax on some scopes, you can read the mirage at one or two intermediate distances, and calculate that way. Get one or both of those books. I think there's another popular one by Bryan Litz, but check into each of them, and see via internet research which one has the type of info you need.
Jim

I know how to read mirage, the issue is you cant always see it in the open air when shooting across a canyon cause your looking for the wind reading in the apex of the bullets flight path. So my issue is how to determine my wind correction for the part of the bullet flight where its trajectory puts it highest up. And to that extent tell me one range in texas open to the public where you can shoot across a canyon, cause shooting across flat ground I do not have a issue with.

Shooting across a canyon story.

I was shooting in the Heat Stroke Open in Elk City, OK two years ago. There were 8 of us in my squad all prone on the edge of a caynon. Out in front of us for about 120 dergeees lay a canyon with targets all throughout, varying from 320 yards to 1050 yards. Everyone took two shots at target "A", then target "B" and so on. I was first up on Target "C" and it lay across the caynon on the hillside of the other side (not skylining) at 650 yards. It was a round 10" plate. I had a right to left wind at my location. I had the parralax clean for the target. I held for right to left wind at the target which was about .6 Mil. Touched it off and splashed it way to the right of the target, like 1 Mil from center (almost 2') I saw it splash, cycled the bolt, held 1.0 Mil left of center and center punched the steel. Jonathan next to me says "wow awesome recovery, you missed by a mile the first time".

What I learned is to check mirage on the other side. You are concered with the wind direction when the bullet is highes in its' arc, and that's good. But there are no wind indicators living there, i.e. trees, grass, bushes. All you have is the mirage on the other side, and it is very helpful up to 12 mph, then it's done telling you anything. Crossing a shot across a canyon, all you can do is judge the wind at your location, and check mirage on the other side.

I've been asked if I had wind flags down my range. My reply is "yep, same ones you have while hunting, grass, tress (large and small) and mirage".

Edit. Where is the bullet most effected by wind? Answer: when it is moving the slowest, thus the reason to check mirage at the target.

looks for bugs and spider webs floating in the air u can usually see something floating in the wind