Ridge Soaring Clouds

Hi Gang
Maybe you do occasionally what I am about to describe or maybe you
have never done it. Regardless it is something you should be aware of.
Firstly a disclaimer. What I am about to describe may be technically
illegal where you fly and I am not suggesting you do it. However it
can be fun.
On a thermal day columns of warm air rise falling in temperature
until dew point is reached and a cloud if formed. Now if there is a
wind gradient with height then the air will flow around the hot column
of air slowly pushing the column of air in the direction of the air
flow. At the cloud the adjacent air will both flow around the cloud
and over the cloud. This usually is very visible by the wedge shape
leading edge of the cloud and the down loops on the trailing edge. Air
ultimately mixes but it take time to do so and the cloud can be viewed
as a hill along the leading edge. Especially when there is a good
vertical wind gradient at cloud level this can provide cloud ridge
soaring possibilities.
So when the clouds indicate a wind gradient climb up to cloud base
as you normally do and make your way to the leading edge and then to
just in front of the leading edge where you should find lift. Then
surf the leading edge getting higher and further back until you are on
top of the cloud and above the cloud. Be very careful not to get
trapped in the cloud which is constantly forming at the leading edge.
Then leave the top of the cloud for another cloud that you can reach
before getting below cloud base and repeat the procedure. Leave each
cloud top from the leading edge direction and not the lee side
otherwise you will find sink.
On a good day and with suitable conditions you can do good distance
flights never going below cloudbase. In general it is slower to do
distance using cloud ridge soaring technigues than normal thermaling
below cloudbase but it can be a blast. A couple of days ago in a far
off southern country I was able to achieve over 2 hours of this type
of soaring arriving back over the field at 12.5k whereas all other
gliders were below 9k. Cloud base was 9k and the maximum height of the
clouds just over 12k.
Comments?
Dave

On Dec 17, 3:13*pm, kd6veb wrote:
Hi Gang
* Maybe you do occasionally what I am about to describe or maybe you
have never done it. Regardless it is something you should be aware of.
Firstly a disclaimer. What I am about to describe may be technically
illegal where you fly and I am not suggesting you do it. However it
can be fun.
* On a thermal day columns of warm air rise falling in temperature
until dew point is reached and a cloud if formed. Now if there is a
wind gradient with height then the air will flow around the hot column
of air slowly pushing the column of air in the direction of the air
flow. At the cloud the adjacent air will both flow around the cloud
and over the cloud. This usually is very visible by the wedge shape
leading edge of the cloud and the down loops on the trailing edge. Air
ultimately mixes but it take time to do so and the cloud can be viewed
as a hill along the leading edge. Especially when there is a good
vertical wind gradient at cloud level this can provide cloud ridge
soaring possibilities.
* So when the clouds indicate a wind gradient climb up to cloud base
as you normally do and make your way to the leading edge and then to
just in front of the leading edge where you should find lift. Then
surf the leading edge getting higher and further back until you are on
top of the cloud and above the cloud. Be very careful not to get
trapped in the cloud which is constantly forming at the leading edge.
Then leave the top of the cloud for another cloud that you can reach
before getting below cloud base and repeat the procedure. Leave each
cloud top from the leading edge direction and not the lee side
otherwise you will find sink.
* On a good day and with suitable conditions you can do good distance
flights never going below cloudbase. In general it is slower to do
distance using cloud ridge soaring technigues than normal thermaling
below cloudbase but it can be a blast. A couple of days ago in a far
off southern country I was able to achieve over 2 hours of this type
of soaring arriving back over the field at 12.5k whereas all other
gliders were below 9k. Cloud base was 9k and the maximum height of the
clouds just over 12k.
* Comments?
Dave

do you have an .igc file of these flights? I'd be interested to know
how your actual L/D compared in the (presumably) smooth air above the
boundary layer vs. the turbulent air below cloudbase.

On Dec 17, 3:31*pm, Tony wrote:
On Dec 17, 3:13*pm, kd6veb wrote:









Hi Gang
* Maybe you do occasionally what I am about to describe or maybe you
have never done it. Regardless it is something you should be aware of.
Firstly a disclaimer. What I am about to describe may be technically
illegal where you fly and I am not suggesting you do it. However it
can be fun.
* On a thermal day columns of warm air rise falling in temperature
until dew point is reached and a cloud if formed. Now if there is a
wind gradient with height then the air will flow around the hot column
of air slowly pushing the column of air in the direction of the air
flow. At the cloud the adjacent air will both flow around the cloud
and over the cloud. This usually is very visible by the wedge shape
leading edge of the cloud and the down loops on the trailing edge. Air
ultimately mixes but it take time to do so and the cloud can be viewed
as a hill along the leading edge. Especially when there is a good
vertical wind gradient at cloud level this can provide cloud ridge
soaring possibilities.
* So when the clouds indicate a wind gradient climb up to cloud base
as you normally do and make your way to the leading edge and then to
just in front of the leading edge where you should find lift. Then
surf the leading edge getting higher and further back until you are on
top of the cloud and above the cloud. Be very careful not to get
trapped in the cloud which is constantly forming at the leading edge.
Then leave the top of the cloud for another cloud that you can reach
before getting below cloud base and repeat the procedure. Leave each
cloud top from the leading edge direction and not the lee side
otherwise you will find sink.
* On a good day and with suitable conditions you can do good distance
flights never going below cloudbase. In general it is slower to do
distance using cloud ridge soaring technigues than normal thermaling
below cloudbase but it can be a blast. A couple of days ago in a far
off southern country I was able to achieve over 2 hours of this type
of soaring arriving back over the field at 12.5k whereas all other
gliders were below 9k. Cloud base was 9k and the maximum height of the
clouds just over 12k.
* Comments?
Dave

do you have an .igc file of these flights? *I'd be interested to know
how your actual L/D compared in the (presumably) smooth air above the
boundary layer vs. the turbulent air below cloudbase.

Sounds kinda like an obstruction wave. Ted Clausing (one of the guys
in my club) managed to get up to over 14K MSL in WI in the early 90s.
There is an article about this in the Feb 1995 Soaring magazine.

http://ssa.org/magazine/archive/View...onth=2&page=33

Pete

On Fri, 17 Dec 2010 13:13:28 -0800, kd6veb wrote:

On a good day and with suitable conditions you can do good distance
flights never going below cloudbase. In general it is slower to do
distance using cloud ridge soaring technigues than normal thermaling
below cloudbase but it can be a blast. A couple of days ago in a far off
southern country I was able to achieve over 2 hours of this type of
soaring arriving back over the field at 12.5k whereas all other gliders
were below 9k. Cloud base was 9k and the maximum height of the clouds
just over 12k.

Never seen it that good, but toward the end of September 2006 I was
flying on a day with good streeting and cloud base at about 3300 ft and
evidently some form of wave activity because a number of the streets had
fairly short side branches at right angles to the main street. By short I
mean 0.6 mile / 1km for the longest ones. I was able to ridge soar the
windward side of the branches, which were around 500 ft deep, and get
almost half way up the face. You're right - its fun.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Dec 17, 1:13*pm, kd6veb wrote:
Hi Gang
* Maybe you do occasionally what I am about to describe or maybe you
have never done it. Regardless it is something you should be aware of.
Firstly a disclaimer. What I am about to describe may be technically
illegal where you fly and I am not suggesting you do it. However it
can be fun.
* On a thermal day columns of warm air rise falling in temperature
until dew point is reached and a cloud if formed. Now if there is a
wind gradient with height then the air will flow around the hot column
of air slowly pushing the column of air in the direction of the air
flow. At the cloud the adjacent air will both flow around the cloud
and over the cloud. This usually is very visible by the wedge shape
leading edge of the cloud and the down loops on the trailing edge. Air
ultimately mixes but it take time to do so and the cloud can be viewed
as a hill along the leading edge. Especially when there is a good
vertical wind gradient at cloud level this can provide cloud ridge
soaring possibilities.
* So when the clouds indicate a wind gradient climb up to cloud base
as you normally do and make your way to the leading edge and then to
just in front of the leading edge where you should find lift. Then
surf the leading edge getting higher and further back until you are on
top of the cloud and above the cloud. Be very careful not to get
trapped in the cloud which is constantly forming at the leading edge.
Then leave the top of the cloud for another cloud that you can reach
before getting below cloud base and repeat the procedure. Leave each
cloud top from the leading edge direction and not the lee side
otherwise you will find sink.
* On a good day and with suitable conditions you can do good distance
flights never going below cloudbase. In general it is slower to do
distance using cloud ridge soaring technigues than normal thermaling
below cloudbase but it can be a blast. A couple of days ago in a far
off southern country I was able to achieve over 2 hours of this type
of soaring arriving back over the field at 12.5k whereas all other
gliders were below 9k. Cloud base was 9k and the maximum height of the
clouds just over 12k.
* Comments?
Dave

I've heard of this being done before..
In the US, 14CFR91.155 would require you to not be closer than 2000ft
horizontal to the cloud when below 10,000 MSL and no closer than 1
mile horizontal above 10,000 MSL. These distances may reduce the
effect of "ridge soaring" on the cloud.

I'd hate to be ridge soaring on a cloud and have someone on an IFR
clearance punch out of the cloud and not see me, nor I him. That's why
the distance requirements.

T

What you are seeing is indeed a type of ridge or wave lift. We see
this all the time here in Oregon. Some of our best wave looks much
more like cumulus than it does lenticulars.

http://www.youtube.com/watch?v=wwPqd48MEUU

Boggs

Dave:

Yes, it's obstruction ridge or wave. The difference is whether it's
on the windward or leeward side of the cloud. The obvious sympton of
wave is laminar flow, which I've flown on the leeward side of large
cloud formations.

Gary: Nice video. Too bad you don't have any MK IV yaw strings --
they look so much more professional than the scotch tape and yarn
variety. Maybe Santa will bring you one!

Fred

I have been dreaming of an MK since the begining of the series, but
will they work on a sheet metal glider like the 2-32? I don't know if
I'm a good enought pilot for a yaw string like that, aren't they hard
to handle?...

Maybe I should write santa a letter?

Boggs

On Dec 17, 1:13*pm, kd6veb wrote:
Hi Gang
* Maybe you do occasionally what I am about to describe or maybe you
have never done it. Regardless it is something you should be aware of.
Firstly a disclaimer. What I am about to describe may be technically
illegal where you fly and I am not suggesting you do it. However it
can be fun.
* On a thermal day columns of warm air rise falling in temperature
until dew point is reached and a cloud if formed. Now if there is a
wind gradient with height then the air will flow around the hot column
of air slowly pushing the column of air in the direction of the air
flow. At the cloud the adjacent air will both flow around the cloud
and over the cloud. This usually is very visible by the wedge shape
leading edge of the cloud and the down loops on the trailing edge. Air
ultimately mixes but it take time to do so and the cloud can be viewed
as a hill along the leading edge. Especially when there is a good
vertical wind gradient at cloud level this can provide cloud ridge
soaring possibilities.
* So when the clouds indicate a wind gradient climb up to cloud base
as you normally do and make your way to the leading edge and then to
just in front of the leading edge where you should find lift. Then
surf the leading edge getting higher and further back until you are on
top of the cloud and above the cloud. Be very careful not to get
trapped in the cloud which is constantly forming at the leading edge.
Then leave the top of the cloud for another cloud that you can reach
before getting below cloud base and repeat the procedure. Leave each
cloud top from the leading edge direction and not the lee side
otherwise you will find sink.
* On a good day and with suitable conditions you can do good distance
flights never going below cloudbase. In general it is slower to do
distance using cloud ridge soaring technigues than normal thermaling
below cloudbase but it can be a blast. A couple of days ago in a far
off southern country I was able to achieve over 2 hours of this type
of soaring arriving back over the field at 12.5k whereas all other
gliders were below 9k. Cloud base was 9k and the maximum height of the
clouds just over 12k.
* Comments?
Dave

http://www.youtube.com/watch?v=JcWTfSYIklo

thermal turned to ridge/wave.

Brad

On Dec 18, 3:21*pm, T wrote:
I'd hate to be ridge soaring on a cloud and have someone on an IFR
clearance punch out of the cloud and not see me, nor I him. That's why
the distance requirements.

I don't know where you are, but around here they don't give IFR
clearances through uncontrolled airspace. If you're soaring where the
big boys might punch out of a cloud then you're in contact with ATC
with with your transponder ON.