How About Story Time

Eric
Good Morning
Like I said I went to 2 of Dick Johnson's camps at Marfa to fly the Shear Wave.
I got about 10 flights in there.
Others please chime in here as I don't really understand these waves, but here is what I know.
They Are Not classic Mt. lee Waves.
Marfa tends to be pretty breezy/ windy in the spring.
At the first pilot meeting Dick asked who had never been here before and after the usual, do this, don't do that, don't crash,pick up your trash talk he had a meeting for us newbies.
He told us to thermal up as high as we could and then instead of putting the nose down and speeding off, keep the nose up and sniff around and try to transition into the shear wave. It is a area that moves about 1/2 the wind speed and is variable from 1-3 knots up. He explained it was caused by a wind shift. Like say in Marfa the wind at 12k might be 270 @ 28, then just above the wind might be say 230 @ 35. I don't understand how but this bounce occurs in Marfa but you S Turn and 360 in this area going up to stay in it, and you can get pretty high. You slowly drift downwind while climbing. And its smooth.
Like I said I don't really understand it- even now, but its there on a regular enough basis to have camps.
Dick and his wife were great and very helpful to me at these camps!
When he saw my Ka6CR he knew it was not the highest performing ship in the fleet so he pulled out my map and marked some places to put it down NE of Marfa if I came up short, which I did one day, which is another story for Story Time.

Le vendredi 1 mai 2020 16:26:49 UTC+2, Nick Kennedy a écritÂ*:
Eric
Good Morning
Like I said I went to 2 of Dick Johnson's camps at Marfa to fly the Shear Wave.
I got about 10 flights in there.
Others please chime in here as I don't really understand these waves, but here is what I know.
They Are Not classic Mt. lee Waves.
Marfa tends to be pretty breezy/ windy in the spring.
At the first pilot meeting Dick asked who had never been here before and after the usual, do this, don't do that, don't crash,pick up your trash talk he had a meeting for us newbies.
He told us to thermal up as high as we could and then instead of putting the nose down and speeding off, keep the nose up and sniff around and try to transition into the shear wave. It is a area that moves about 1/2 the wind speed and is variable from 1-3 knots up. He explained it was caused by a wind shift. Like say in Marfa the wind at 12k might be 270 @ 28, then just above the wind might be say 230 @ 35. I don't understand how but this bounce occurs in Marfa but you S Turn and 360 in this area going up to stay in it, and you can get pretty high. You slowly drift downwind while climbing. And its smooth.
Like I said I don't really understand it- even now, but its there on a regular enough basis to have camps.
Dick and his wife were great and very helpful to me at these camps!
When he saw my Ka6CR he knew it was not the highest performing ship in the fleet so he pulled out my map and marked some places to put it down NE of Marfa if I came up short, which I did one day, which is another story for Story Time.

I had a similar thing in Norther Germany (which is as flat as flat can get)..
Wind shear at a little less than cloudbase (with well developed streets) created a wave with the Cu clouds as obstacles, and I was able to climb 2000 ft above cloud base.

This has also been experienced in extreme South Florida, appx. 90 degree windshift at top of convection. I don't think there are secondary, tertiary - perhaps not "wave", but laminar flow over the top of the intruding mixed layer?

On Friday, May 1, 2020 at 7:26:49 AM UTC-7, Nick Kennedy wrote:
Eric
Good Morning
Like I said I went to 2 of Dick Johnson's camps at Marfa to fly the Shear Wave.
I got about 10 flights in there.
Others please chime in here as I don't really understand these waves, but here is what I know.
They Are Not classic Mt. lee Waves.
Marfa tends to be pretty breezy/ windy in the spring.
At the first pilot meeting Dick asked who had never been here before and after the usual, do this, don't do that, don't crash,pick up your trash talk he had a meeting for us newbies.
He told us to thermal up as high as we could and then instead of putting the nose down and speeding off, keep the nose up and sniff around and try to transition into the shear wave. It is a area that moves about 1/2 the wind speed and is variable from 1-3 knots up. He explained it was caused by a wind shift. Like say in Marfa the wind at 12k might be 270 @ 28, then just above the wind might be say 230 @ 35. I don't understand how but this bounce occurs in Marfa but you S Turn and 360 in this area going up to stay in it, and you can get pretty high. You slowly drift downwind while climbing. And its smooth.
Like I said I don't really understand it- even now, but its there on a regular enough basis to have camps.
Dick and his wife were great and very helpful to me at these camps!
When he saw my Ka6CR he knew it was not the highest performing ship in the fleet so he pulled out my map and marked some places to put it down NE of Marfa if I came up short, which I did one day, which is another story for Story Time.

Anyone who has driven on washboard dirt roads has experienced shear wave. The car tires moving in a different direction from the stationary dirt road.. That makes the washboard bumps in the road. Not that I understand it. I also saw this in a wave tank with salt and fresh water as a the the lighter water passed over the lower heavier water. *Don Altman, SIO grad student, Hydro Lab, 1983. Wonder where he is today.)
Steve

On Saturday, April 4, 2020 at 2:40:32 PM UTC-4, wrote:
Maybe this is a good opportunity for some of us to share some stories of our experiences.
I'll go first.-

During the regional at Harris Hill in 2013 I was flying K21 with grandson Calvin Mampe, Rachel Conklin, and her sister Michelle. All 3 had flown multiple contests with me before, 2 having done so before they were old enough to solo.
Half way through the contest, my wife Dianne had a terrible fall and ended up hospitalized with some very serious injuries. All 3 of the juniors had good flights with me earlier in the contest so I told them to just keep on flying.
On Friday, Calvin and Rachel flew but decided to abandon the task part way around the course due to rain. They did not want to land out and take the ship apart in the rain. Smart!
The next day Rachel and Michelle flew together. About 4:00 I was in the ICU with Dianne when Calvin called. When I answered, he simply said “K21 four miles�. Our 2 young ladies had flown the course for a reasonable score. To my knowledge, this is the first time two young sisters had ever flown in competition. We had a seriously great group hug that night. This may be my best ever moment as a supporter of youth soaring.
Following up- Michelle is now an A&P working for Textron and just finished her first restoration, a 1-26E. Rachel is instructing at Flight Safety and soon will have all the requirements for her ATP.

UH

This is often called "thermal wave" as it seems to need thermals to
get it going; it used to be a fairly frequent occurence in Eastern Canada
in the '70s and 80s.
In 1977 on a day with cloud streets at 7000 ft, I transitioned into
weak wave at cloudbase. It got better high up and I was still climbing 2kts
at 16K; the Cu had become lennies stretching as far as one could see.
I published a paper with the met. details at the 1978 Ostiv conf..

Despite regular flying in the last 20 years, I have not encountered
any thermal wave since! Climate change?

John Firth

On Friday, May 1, 2020 at 7:15:18 PM UTC+1, john firth wrote:
On Saturday, April 4, 2020 at 2:40:32 PM UTC-4, wrote:
Maybe this is a good opportunity for some of us to share some stories of our experiences.
I'll go first.-

During the regional at Harris Hill in 2013 I was flying K21 with grandson Calvin Mampe, Rachel Conklin, and her sister Michelle. All 3 had flown multiple contests with me before, 2 having done so before they were old enough to solo.
Half way through the contest, my wife Dianne had a terrible fall and ended up hospitalized with some very serious injuries. All 3 of the juniors had good flights with me earlier in the contest so I told them to just keep on flying.
On Friday, Calvin and Rachel flew but decided to abandon the task part way around the course due to rain. They did not want to land out and take the ship apart in the rain. Smart!
The next day Rachel and Michelle flew together. About 4:00 I was in the ICU with Dianne when Calvin called. When I answered, he simply said “K21 four miles�. Our 2 young ladies had flown the course for a reasonable score. To my knowledge, this is the first time two young sisters had ever flown in competition. We had a seriously great group hug that night. This may be my best ever moment as a supporter of youth soaring.
Following up- Michelle is now an A&P working for Textron and just finished her first restoration, a 1-26E. Rachel is instructing at Flight Safety and soon will have all the requirements for her ATP.

UH

This is often called "thermal wave" as it seems to need thermals to
get it going; it used to be a fairly frequent occurence in Eastern Canada
in the '70s and 80s.
In 1977 on a day with cloud streets at 7000 ft, I transitioned into
weak wave at cloudbase. It got better high up and I was still climbing 2kts
at 16K; the Cu had become lennies stretching as far as one could see.
I published a paper with the met. details at the 1978 Ostiv conf..

Despite regular flying in the last 20 years, I have not encountered
any thermal wave since! Climate change?

John Firth

I don't think that shear wave is necessarily dependent on thermals below it.. I have seen otherwise inexplicable clearly delineated shear wave in the early mornings over flat central South Africa long before the thermals got going. This upper wave system persisted after the thermals started but the base of it, and top of the thermals, were above the 14500ft (10,000 agl) airspace limit.

On Friday, May 1, 2020 at 1:15:18 PM UTC-5, john firth wrote:
On Saturday, April 4, 2020 at 2:40:32 PM UTC-4, wrote:
Maybe this is a good opportunity for some of us to share some stories of our experiences.
I'll go first.-

During the regional at Harris Hill in 2013 I was flying K21 with grandson Calvin Mampe, Rachel Conklin, and her sister Michelle. All 3 had flown multiple contests with me before, 2 having done so before they were old enough to solo.
Half way through the contest, my wife Dianne had a terrible fall and ended up hospitalized with some very serious injuries. All 3 of the juniors had good flights with me earlier in the contest so I told them to just keep on flying.
On Friday, Calvin and Rachel flew but decided to abandon the task part way around the course due to rain. They did not want to land out and take the ship apart in the rain. Smart!
The next day Rachel and Michelle flew together. About 4:00 I was in the ICU with Dianne when Calvin called. When I answered, he simply said “K21 four miles�. Our 2 young ladies had flown the course for a reasonable score. To my knowledge, this is the first time two young sisters had ever flown in competition. We had a seriously great group hug that night. This may be my best ever moment as a supporter of youth soaring.
Following up- Michelle is now an A&P working for Textron and just finished her first restoration, a 1-26E. Rachel is instructing at Flight Safety and soon will have all the requirements for her ATP.

UH

This is often called "thermal wave" as it seems to need thermals to
get it going; it used to be a fairly frequent occurence in Eastern Canada
in the '70s and 80s.
In 1977 on a day with cloud streets at 7000 ft, I transitioned into
weak wave at cloudbase. It got better high up and I was still climbing 2kts
at 16K; the Cu had become lennies stretching as far as one could see.
I published a paper with the met. details at the 1978 Ostiv conf..

Despite regular flying in the last 20 years, I have not encountered
any thermal wave since! Climate change?

John Firth

My first flight instructor, Ed Gaddy, frequently described thermal wave. Since Ed told me about it, I have always looked for it. It is there more often than we think. I have encountered usable wave-like lift that goes above cloudbase most years and have seen it nearly every place that I have soared in the U.S. Best case was in Eastern North Carolina in 1987. I was flying an SGS-123D. Wind out of the East on the ground, brisk, maybe 15 knots. Gorgeous cloud streets forming. Textbook lenticular clouds on top of each cu. Climbed up to cloudbase at 5000'. Explored out away from the upwind edge of the cloud, about 90 degrees to the wind direction below cloudbase, and found weak, smooth lift, flew back and forth climbing slowly, lift gradually increased to a whole 2 knots. Eventually made it to 8000' several hundred feet below the leading edge of the lennies. Was able to fly along the top of the streets for miles. A couple seasons ago, at a GTA event, I was able to climb my H301 about 1000' above cloudbase. Two towering cu's merged at their bottoms and tops to form one big cloud with a tunnel through it. Flew through that mile long tunnel in zero sink. That was fun, but exceedingly weird.. Kinda like a surfer in the tube.

On Friday, May 1, 2020 at 2:15:18 PM UTC-4, john firth wrote:
This is often called "thermal wave"...

https://www.ssa.org/Contests?show=blog&id=4169

On Friday, May 1, 2020 at 11:52:26 AM UTC-7, Dave Nadler wrote:
On Friday, May 1, 2020 at 2:15:18 PM UTC-4, john firth wrote:
This is often called "thermal wave"...

https://www.ssa.org/Contests?show=blog&id=4169

Thank you, Dave, for that write-up.

On the Canadian prairies, the clue to thermal wave is a shift in cloud orientation. Takes a bit of wind, so typically a day with well defined streets up and down the wind. Abruptly, over a period of only half an hour or so, the skyscape changes - perhaps all of it, perhaps only one large area - to bands of cloud across the wind. Time to go wave hunting! Pressing forward into wind at cloud base, as others have said.

Sometimes, rather dramatic lennies cap the cu, but not always, and not the first clue.

Cheers, Bruce

I have seen lennies over tcu and cb countless times - but never any indication of secondary, tertiary wave action. Only reason I'm not calling it "wave"...