Avoiding turbulence.

EdFred

EdFred

Taxi to Parking
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Maybe I missed this in my all my training, or maybe I read it and forgotten it, and maybe it was coincidence. I keep meaning to throw this out there, but kept forgetting. Anyway...

Coming home from 6Y9 at the end of the July 4th weekend, it was pretty windy and gusty down low, and I was going to head over to SAW to get fuel and check weather before heading back south. Like I said surface winds were pretty gusty, and down low there was quite a bit of orographic turbulence. It was also one of those 85ish degree days where the bases of the cumuli were 7000 or so feet. I wasn't going to bother to get on top for a 55 mile flight, so I was just riding out the bumps at 5500 or so on my way to Sawyer. I looked up and saw that the clouds had aligned themselves in rows, running in my direction of travel. I got in between the rows (although still below them) and the turbulence went away.

So, is this something that I missed/forgot/never covered, or was it just coincidence? Feel free to chime in.
 
Ahhh you found cloud streets. Us sailplane guys use the stretch under the clouds for fast cross country speeds. Basically thermals will line up with the wind. The resulting street will have lots of lift (turbulence) beneath it. the area in between the streets will generally be filled with sinking (less bumpy) air.
 
Ed, a cumulus cloud is an indicator of rising air. Rising air causes turbulance. The right conditions, on a windy day, can form what is known as a cloud street which are lines of clouds parallel with the wind.

If you were a glider you would have gotten underneath the cloud and followed that cloud-street hauling ass in the non-stop thermal. This would even work not in a glider. If you would have just gotten underneath that street you'd likely get a decent airspeed gain if you converted the updrafts into forward energy.
 
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ed what you were observing is what glider pilots call cloud streets. when there is strong winds the thermals tend to align themselves with the wind, making "streets" of lift, resulting in streets of clouds. Airplane pilots refer to lift as turbulence. Between the clouds is the sinking air associated with these updrafts. I suspect since sinking air is by definition more stable air, you encountered less turbulence. you also had to fly slightly slower than you wouldve in truly smooth air because the airplane was likely climbing a couple hundred feet per minute for the 55 mile trip.
 
In this case the sidewalks were smoother than the streets, and I didn't feel like cleaning up dog vomit, and took the speed penalty - which was negligible since I had a 35kt tailwind.
 
EdFred said:
In this case the sidewalks were smoother than the streets, and I didn't feel like cleaning up dog vomit, and took the speed penalty - which was negligible since I had a 35kt tailwind.
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Don't blame you. I often will take the smooth air even if it means a headwind. I'd rather enjoy the flight -- if it takes longer -- oh well.
 
vontresc said:
Ahhh you found cloud streets. Us sailplane guys use the stretch under the clouds for fast cross country speeds. Basically thermals will line up with the wind. The resulting street will have lots of lift (turbulence) beneath it. the area in between the streets will generally be filled with sinking (less bumpy) air.
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jesse said:
Ed, a cumulus cloud is an indicator of rising air. Rising air causes turbulance. The right conditions, on a windy day, can form what is known as a cloud street which are lines of clouds parallel with the wind.

If you were a glider you would have gotten underneath the cloud and followed that cloud-street hauling ass in the non-stop thermal. This would even work not in a glider. If you would have just gotten underneath that street you'd likely get a decent airspeed gain if you converted the updrafts into forward energy.
Click to expand...

tonycondon said:
ed what you were observing is what glider pilots call cloud streets. when there is strong winds the thermals tend to align themselves with the wind, making "streets" of lift, resulting in streets of clouds. Airplane pilots refer to lift as turbulence. Between the clouds is the sinking air associated with these updrafts. I suspect since sinking air is by definition more stable air, you encountered less turbulence. you also had to fly slightly slower than you wouldve in truly smooth air because the airplane was likely climbing a couple hundred feet per minute for the 55 mile trip.
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Ed, after my extensive training in weather phenomena, it is my expert opinion that what you were dealing with are commonly known as 'cloud streets'. I will also let you in on a little secret that VERY few people know about (I may be the only one with this information) - glider pilots actually prefer to use the cloud streets to obtain long-distance flights - also known as 'cross-country' flights to us educated types.

I hope I have enlightened you to a very obscure bit of information that very few people are keen to.

:D :D :D
 
"La Rue de Cloud."







:D
 
Ed,

Let me take this opportunity to tell you about a little thing called a "cloud street"...
 
Ed check with some glider pilots here Tony or Pete I think you found something called a Cloud Road the area between the coulds is less turbulent.:D
 
Just remember, ya can't never trust those glider guys. Heck, their own society makes'em use sealed instruments and stuff!
 
AFaIK cloud streets are essentially the result of a relatively low intensity "mountain wave" (i.e. the oscillatory aftermath of some vertical disturbance further upwind) coupled with airborne dewpoints near the air temperature.
 
scottd said:
Sometimes, but not necessarily all the time. Non-turbulent lee waves are a perfect example of air that has a vertical component, but may be very smooth. Turbulence (bumps) is typically created as a result of mixing or the interaction of rising air with the prevailing wind. And yes, thermals interacting with the prevailing wind are what normally causes the turbulence we feel down low or in cumuliform clouds.
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Agree--perfectly constant rising air would be smooth. IME though it is very rare to experience perfectly constant rising air.
 
scottd said:
No, it is not something covered in your basic pilot training...:frown3:

I get this question a lot, so I decided to create an e-Tip explaining it a little. BTW, cloud streets are not mountain waves. They are formed when a capping stable layer forms under an unstable layer.

What was your approximate time (day and zulu time) of your trip...may be able to look up a satellite image or two.
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Sunday July 5th somewhere between 16z and 22z west of SAW
 
CJones said:
Ed, after my extensive training in weather phenomena, it is my expert opinion that what you were dealing with are commonly known as 'cloud streets'. I will also let you in on a little secret that VERY few people know about (I may be the only one with this information) - glider pilots actually prefer to use the cloud streets to obtain long-distance flights - also known as 'cross-country' flights to us educated types.

I hope I have enlightened you to a very obscure bit of information that very few people are keen to.

:D :D :D
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Geesh Ed, cloud streets. Even I knew that.

(especially after reading this thread). :D
 
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Ed,

Cloud Streets, rough travel, Michigan.

What else is there to say.

Oh, watch out for the Barrels.:blush:

Ray
 
Jesse,

You need to experience mountain wave. I did once at Minden and it was the smoothest smooth I was ever in and the altimeter was cranking on up. The only noise was the variometer which was actually fun to listen to.

Rick
 
B2Soar said:
Jesse,

You need to experience mountain wave. I did once at Minden and it was the smoothest smooth I was ever in and the altimeter was cranking on up. The only noise was the variometer which was actually fun to listen to.

Rick
Click to expand...

So how was the rotor on the way to the wave, Rick?
 
Missed the rotor Pete,

Towed to 3000agl. Worked 1 to 5 knot lift up to 9000' msl and just suddenly "hit the cotton". Words just do not do it justice. It is something you have to do to believe.

Rick
 
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