Disc changing altitude suddenly...

[Jamesein]

For about the last three months i have noticed something odd on alot of my throws, the disc will change altitude suddenly mid flight, I.E it will either drop suddenly atleast 2+ feet or rise the same amount of distance sometimes two or three times during the flight, i was thinking it might be the wind either batting it down or catching an updraft and raising it up but it happens whenever there is no wind, I also think it might have something to do with the spin of the disc but I really doubt im getting that kind of snap on my throws, so i was wondering if anyone could lay some science down, or atleast some know how to answer this question, I really didnt know where to post this, i figured the answer lies somewhere in my technique good or bad, Thank you!

[CatPredator]

If it's going up and down multiple times on a throw it's wind...whether you feel it where you're standing or not.

Wind speed drops the closer you get to the ground. The higher you throw your disc, the more likely you are going to run into some turbulence. Trees and terrain can shelter the lower portions of a course too, but if you get up to an area where the wind is unobstructed you can catch some swirls.

[jaydub803]

There is a school near me with a 9 hole in a field that has a hill on one side. If you are throwing across the field at hole 6 you are throwing across a large flat area with the hill behind the basket. I can throw my mids or fairways on a line drive to the basket low, and if the wind is coming at me head on, the disc will get about 100 feet out from me at around 20 feet of height, then zoom WAY up in the air striaght up when the wind down the hill catches it. It will get up like 50 or 60 feet and turn sideways if the gusts are bad. Its crazy seeing a sucky throw heading down short of the basket, only to get picked up and dropped again over a hundred feet from where you thought.

[JHern]

If it's going up and down multiple times on a throw it's wind...whether you feel it where you're standing or not...

^ Indeed.

I've been studying disc flight for a while now, and one of the interesting things to come out of it is that the disc tends to pop into the trajectory that balances the aerodynamic lift and gravity forces, and stays there for most of the flight. The lift force changes as you change the angle of attack and speed of the disc relative to the surrounding air (air velocity=disc velocity minus wind velocity). Of course the disc slows with time owing to aerodynamic drag, and rising or settling of the disc also alters the angle of attack, so this balance is always a moving target. A disc tends to pop into this state of balance pretty fast (less than a second), and once it is there the only thing that can make it move up and down a lot is wind, which changes the lift and alters the balance. In fact, the time the disc takes to pop up or down in flight due to wind disturbances is representative of the time it takes for the disc to pop into a balance between lift and gravity when it finds itself not in balance.

[JR]

Isn't OKC a very very windy place? I live by the sea and that is normal but not all discs respond to different wind directions similarly. Some cope with rear winds, some with front winds, some with each wind and some die in each wind condition. Z Force is even better than the Halo, the favorite disc of the OP, for wind neutrality. Zone and the most overstable kinds of Gators are good too. Pigs are fine as well. I think Z Wasp will be great. It took me this long to get my first one and in 17 MPH winds from different directions between rear and right winds it was surprisingly nice. Especially considering the lousy footing.

[jaydub803]

Man, I scored a couple of gummy champ rhinos for the wind this weekend, and those bitches act like the wind isn't there. I ended up dropping all my mids for the day and used the rhynos for all putt and approach, they don't hop up and down in the air at all, and a flip shot stays flipped til the last second. I made two 40+ foot putts after throwing my kc aviars which overfloated by at least 20 feet. ANyway, had to rave. Back on topic...