longranger
Well Known Member
IMHO, sealing tanks would be more fun than flying around this thing.
Tehachapi, CA, Nov. 14 2009
Tehachapi, CA, Nov. 14 2009
Van's Air Force
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Think I'll Stay on the Ground Today
- Thread starter longranger
- Start date
AltonD
Well Known Member
lenticular. Turbulence. Stay out. Usually forms over mountain range peaks.
http://en.wikipedia.org/wiki/Lenticular_cloud
http://en.wikipedia.org/wiki/Lenticular_cloud
David Clifford
Well Known Member
Lenticular cloud
From Wikipedia, the free encyclopedia
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Lenticular cloud
Lenticular cloud above northern Presidential Range, NH
Genus Alto- (Latin for high)
-cumulus (Latin: heap)
Species lenticularis (Latin: lens-shaped)
Altitude 6,000-12,000 m
(20,000-40,000 ft)
Classification Family A (High-level)
Appearance lens-like
Precipitation cloud? Sometimes
This box: view ? talk
Altocumulus lenticularis often forms in the lee of mountains.Lenticular clouds are stationary lens-shaped clouds that form at high altitudes, normally aligned perpendicular to the wind direction. Lenticular clouds can be separated into altocumulus standing lenticularis (ACSL), stratocumulus standing lenticular (SCSL), and cirrocumulus standing lenticular (CCSL).
Contents [hide]
1 Formation
2 Flight
3 Gallery
4 See also
5 References
6 External links
[edit] Formation
Where stable moist air flows over a mountain or a range of mountains, a series of large-scale standing waves may form on the downwind side. If the temperature at the crest of the wave drops to or below the dew point, moisture in the air may condense to form lenticular clouds. As the moist air moves back down into the trough of the wave, the cloud may evaporate back into vapor. Under certain conditions, long strings of lenticular clouds can form near the crest of each successive wave, creating a formation known as a 'wave cloud'. The wave systems cause large vertical air movements and so enough water vapor may condense to produce precipitation. The clouds have been mistaken for UFOs (or "visual cover" for UFOs) because these clouds have a characteristic lens appearance and smooth saucer-like shape. Bright colors (called Irisation) are sometimes seen along the edge of lenticular clouds.[1]
[edit] Flight
Power pilots tend to avoid flying near lenticular clouds because of the turbulence of the rotor systems that accompany them, but sailplane pilots actively seek them out. The precise location of the rising air mass is fairly easy to predict from the orientation of the clouds. "Wave lift" of this kind is often very smooth and strong, and enables gliders to soar to remarkable altitudes and great distances. The current gliding world records for both distance (over 3,000 km; 1,864 mi) and altitude (15,460 m; 50,721 ft) were set using such lift[2].
I bet the soaring guys were having fun though!
the_other_dougreeves
Well Known Member
johnny stick
Well Known Member
Enough lift for an airliner
There is an urban legion that Boeing flew a 707-type airliner in the wave lift from a the sierra nevada mountains. they are great gas savers, but make sure you know where the rotors are. many gliders have been torn apart in the rotor. Been towed through a very small rotor once over Rosamond,near techacapi, never again.
There is an urban legion that Boeing flew a 707-type airliner in the wave lift from a the sierra nevada mountains. they are great gas savers, but make sure you know where the rotors are. many gliders have been torn apart in the rotor. Been towed through a very small rotor once over Rosamond,near techacapi, never again.
Oh yeah, wave flying is great! Here is what these clouds look like from above:
By the way, flying in the wave is wonderful smooth and completely laminar. It's the rotors that can be violently turbulent, and you find them mostly below the peaks of the wave, but it's even possible to have wave without any rotor:
Hendrik
jjconstant
Well Known Member
rotor question
So, is there a rule of thumb for avoiding rotors? Fly only above the visible cloud or above the height of the peaks? Do the rotors only develop at or below the height of the peaks?
Jeremy Constant
So, is there a rule of thumb for avoiding rotors? Fly only above the visible cloud or above the height of the peaks? Do the rotors only develop at or below the height of the peaks?
Jeremy Constant
scsmith
Well Known Member
Rotors generally at and below peak height
I've done a LOT of rotor rooting and wave flying in my glider.
Generally, the rotor is at heights from somewhat below the ridge height, to perhaps some height above it. Complicating things is that there are also thermals that extend from the ground, come up upwind of the rotor, to some extent blend with it, and continue upward for some height - usually enough to allow a nice transition into the wave itself.
If you come into the lift area at a height above ridge level, just climb into the elevator. You will feel the wave itself, it gets really really smooth. When you know what you are doing, you can make incredible ground speeds with very low fuel burn.
Flying into the rotor at cruising speed would be indeed violent. You need to slow down to approx. Vy. Then, the real enemy is staying out of the sink. What goes up must go down so expect to stumble into areas of 2000 ft/min sink. Speed up and get out of there, do not sit and try to climb there.
I've done a LOT of rotor rooting and wave flying in my glider.
Generally, the rotor is at heights from somewhat below the ridge height, to perhaps some height above it. Complicating things is that there are also thermals that extend from the ground, come up upwind of the rotor, to some extent blend with it, and continue upward for some height - usually enough to allow a nice transition into the wave itself.
If you come into the lift area at a height above ridge level, just climb into the elevator. You will feel the wave itself, it gets really really smooth. When you know what you are doing, you can make incredible ground speeds with very low fuel burn.
Flying into the rotor at cruising speed would be indeed violent. You need to slow down to approx. Vy. Then, the real enemy is staying out of the sink. What goes up must go down
so expect to stumble into areas of 2000 ft/min sink. Speed up and get out of there, do not sit and try to climb there.
flion
Well Known Member
Stay away from the lee side of ridges. Rotors can exist without lenticulars to mark them. If you must go near a ridgeline, try to cross perpendicular and stay below maneuvering speed. As that graphic shows, the most violent part of the rotor is near the surface; altitude is your friend. As for the lenticular cloud itself, usually it's pretty stable there (but you have to stay clear for VFR). Sometimes, though, you can see the back edge all ragged and visibly 'working' ... good indication of turbulence.
For a graphic demonstration of how this works, find a smooth, fast-running stream of water and stick your hand in perpendicular to the flow just under the surface. You'll see the water lift over your hand and then fall back into a roil and, if the water is fast and smooth enough, usually a series of lesser waves after that.
Yesterday, flying Flagstaff to Kidwell, I could feel a series of waves as I got near Lake Mohave at 10,500. Usually they were co-located with some feature such as the mountain south of Seligman. Then I descended and just as I got to about 6000 and passed the ridge east of Kidwell, I got some fairly moderate chop. The prevailing wind was down the valley and was probably 'tripped' at the north end; the whole valley was choppy. When we left, I climbed as fast as possible and by the time I got to 6500 I was in smooth air again, even though I was still over the valley. Looking for smooth and and/or living with the chop in the mountains is a bit of an art and actually part of the fun of flying around here ... when it doesn't wear you out.
For a graphic demonstration of how this works, find a smooth, fast-running stream of water and stick your hand in perpendicular to the flow just under the surface. You'll see the water lift over your hand and then fall back into a roil and, if the water is fast and smooth enough, usually a series of lesser waves after that.
Yesterday, flying Flagstaff to Kidwell, I could feel a series of waves as I got near Lake Mohave at 10,500. Usually they were co-located with some feature such as the mountain south of Seligman. Then I descended and just as I got to about 6000 and passed the ridge east of Kidwell, I got some fairly moderate chop. The prevailing wind was down the valley and was probably 'tripped' at the north end; the whole valley was choppy. When we left, I climbed as fast as possible and by the time I got to 6500 I was in smooth air again, even though I was still over the valley. Looking for smooth and and/or living with the chop in the mountains is a bit of an art and actually part of the fun of flying around here ... when it doesn't wear you out.
erich weaver
Well Known Member
This background photo on this web site shows the mother of all lenticular clouds
http://biglar.homestead.com/Larry.html
erich
http://biglar.homestead.com/Larry.html
erich
Rotors can reach from the ground to quite a bit higher than the mountain peaks, but I wouldn't expect them at the altitude of the lenticularis cloud. Rule of the thumb is: The higher, the smoother. Sometimes rotor clouds form, which give you at least a hint about the position of the rotor. Have a look at this image:
This picture shows a beautiful rotor cloud. You can see the rough edges and frazzles, and often one can see the whole cloud rotating. But it's more common to have only small pieces of clouds in the rotor which look like a very broken street of strangely shaped cumulus clouds perpendicular to the wind direction. And often the rotor is clear and there is no visible sign at all!
On the particular day when I shot that picture the rotor extended up to about 6000 ft whereas the highest mountain peak in that area is 3600 ft. In that rotor I experienced within seconds both sink and lift of up to 3000 ft/min, and some lift of 3500 ft/min. For a glider who wants to use the rotor lift to enter the wave it is essential to stay on the front side of the rotor, trying to avoid the center and the sink region by all means. In the lift region it's like an elevator ride. Another pilot told us in the evening that he got inverted by the rotor. Rotors are definitely not something to fly straight through (or at all to fly into unprepared), and you better don't have any loose objects in the cockpit. They can be violent.
Now compare the first picture to this one:
Same location, different day. On this day there was a slight rotor, barely noticeable and with only few visual signs. If you look closely you can see a tiny bit of a rotor cloud at the right edge of the picture, and also the low clouds on the left show some turbulence. But the main thing you can see is the lenticularis cloud. Very smooth shape, stationary with respect to the ground (well, so is the rotor, too). Note that even through the lenticularis is stationary over the ground, the wind speeds up there can be rather high. The cloud constantly forms at the luv side (where the lift is) and decays at the lee side (where the sink is). It's not uncommon to sit in the glider in absolutely smooth air, nose into the wind, going up at 50-60 kts IAS and zero ground speed. On that day we went up to 17000 ft within 20 minutes or so.
Having said that, there can be rotors and waves in a totally blue sky, so stay high and take care.
Hendrik
This picture shows a beautiful rotor cloud. You can see the rough edges and frazzles, and often one can see the whole cloud rotating. But it's more common to have only small pieces of clouds in the rotor which look like a very broken street of strangely shaped cumulus clouds perpendicular to the wind direction. And often the rotor is clear and there is no visible sign at all!
On the particular day when I shot that picture the rotor extended up to about 6000 ft whereas the highest mountain peak in that area is 3600 ft. In that rotor I experienced within seconds both sink and lift of up to 3000 ft/min, and some lift of 3500 ft/min. For a glider who wants to use the rotor lift to enter the wave it is essential to stay on the front side of the rotor, trying to avoid the center and the sink region by all means. In the lift region it's like an elevator ride. Another pilot told us in the evening that he got inverted by the rotor. Rotors are definitely not something to fly straight through (or at all to fly into unprepared), and you better don't have any loose objects in the cockpit. They can be violent.
Now compare the first picture to this one:
Same location, different day. On this day there was a slight rotor, barely noticeable and with only few visual signs. If you look closely you can see a tiny bit of a rotor cloud at the right edge of the picture, and also the low clouds on the left show some turbulence. But the main thing you can see is the lenticularis cloud. Very smooth shape, stationary with respect to the ground (well, so is the rotor, too). Note that even through the lenticularis is stationary over the ground, the wind speeds up there can be rather high. The cloud constantly forms at the luv side (where the lift is) and decays at the lee side (where the sink is). It's not uncommon to sit in the glider in absolutely smooth air, nose into the wind, going up at 50-60 kts IAS and zero ground speed. On that day we went up to 17000 ft within 20 minutes or so.
Having said that, there can be rotors and waves in a totally blue sky, so stay high and take care.
Hendrik
Wow, that one is awesome!!
Alex Caldwell
Member
The cloud you photographed that day was also clearly visible, along
with it's shadow, on this beautiful picture from the Modis Aqua satellite.
It's a huge picture. You'll have to center it on the Tehachapi area to see the
cloud.
http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=AERONET_Fresno.2009318.aqua.250m
with it's shadow, on this beautiful picture from the Modis Aqua satellite.
It's a huge picture. You'll have to center it on the Tehachapi area to see the
cloud.
http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=AERONET_Fresno.2009318.aqua.250m
Alex Caldwell
Member
Predicting Waves
There is a meteorlogist/soaring pilot named John Glendening, also known as
"Dr. Jack", that is experimenting with a computer weather modeling system
known as "WRF" that can predict the location and strength of waves. When
you get an ordinary weather briefing, you will get a
very generalized warning about waves if the winds are forecast to be strong,
but where EXACTLY are they going to be, and how strong? Sailplane pilots
generally learn when to expect wave from their experience flying in a familiar local
area over time, in various types of synoptic situations, like frontal passages etc.
But what if you are a flatlander flying into an unfamiliar mountainous area 2 days from now?
Dr. Jack is using
a model he calls "RASP" based on a computer model from the government
called "WRF" which takes the terrain into account, along with the winds, and
things like atmospheric temperature lapse rates, and tries to predict where you will
encounter waves. The computer model requires a lot of computing resources,
so he has farmed out the job to
a number of volunteers who have set up RASP "grids" on their own computers
for certain local areas
of interest. There are some areas of the country near popular gliding spots
that are pretty well covered, such as the Sierras, the San Francico Bay Area
of Calif., the Sacramento Valley area, Central Calif., Southern Calif., the front
range of the Rockies etc. that have daily RASP reports available.
There are some links to some of the sites available here. Most of them have
forecasts up to 2 days ahead. CAUTION - this is EXPERIMENTAL,
DO NOT RELY ON THESE FOR YOUR LIFE OR LIMB!
http://www.drjack.info/RASP/index.html
To see about wave, go to the forecasts labeled "Wave Parameters"
for lower level wave activity look at the "vertical velocity at 850mb"
For higher altitudes look at "vertical velocity at 700mb" and "vertical velocity
at 500mb" also the "vertical velocity slice at vert. vel. max" takes a slice
through the area of maximal wind velocity for the grid area at the forecast time.
Areas in varying shades of red are areas of upward velocity (lift) likely to be
wave. Areas in varying shades of blue and darkening to purple are areas of sink.
The rotor is generally located under the area where the lift transitions
back into sink. But the RASP does not try to predict the location or altitude
band of the Rotor specifically. I looked at Sat. Nov 14 forecast for the
Nothern San Diego/LA region and the Santa Barbara region, and the wave
that day was forecast pretty accurately 2 days ahead of time on the RASP.
Alex Caldwell
CFI-G
RV-3a N1131T
There is a meteorlogist/soaring pilot named John Glendening, also known as
"Dr. Jack", that is experimenting with a computer weather modeling system
known as "WRF" that can predict the location and strength of waves. When
you get an ordinary weather briefing, you will get a
very generalized warning about waves if the winds are forecast to be strong,
but where EXACTLY are they going to be, and how strong? Sailplane pilots
generally learn when to expect wave from their experience flying in a familiar local
area over time, in various types of synoptic situations, like frontal passages etc.
But what if you are a flatlander flying into an unfamiliar mountainous area 2 days from now?
Dr. Jack is using
a model he calls "RASP" based on a computer model from the government
called "WRF" which takes the terrain into account, along with the winds, and
things like atmospheric temperature lapse rates, and tries to predict where you will
encounter waves. The computer model requires a lot of computing resources,
so he has farmed out the job to
a number of volunteers who have set up RASP "grids" on their own computers
for certain local areas
of interest. There are some areas of the country near popular gliding spots
that are pretty well covered, such as the Sierras, the San Francico Bay Area
of Calif., the Sacramento Valley area, Central Calif., Southern Calif., the front
range of the Rockies etc. that have daily RASP reports available.
There are some links to some of the sites available here. Most of them have
forecasts up to 2 days ahead. CAUTION - this is EXPERIMENTAL,
DO NOT RELY ON THESE FOR YOUR LIFE OR LIMB!
http://www.drjack.info/RASP/index.html
To see about wave, go to the forecasts labeled "Wave Parameters"
for lower level wave activity look at the "vertical velocity at 850mb"
For higher altitudes look at "vertical velocity at 700mb" and "vertical velocity
at 500mb" also the "vertical velocity slice at vert. vel. max" takes a slice
through the area of maximal wind velocity for the grid area at the forecast time.
Areas in varying shades of red are areas of upward velocity (lift) likely to be
wave. Areas in varying shades of blue and darkening to purple are areas of sink.
The rotor is generally located under the area where the lift transitions
back into sink. But the RASP does not try to predict the location or altitude
band of the Rotor specifically. I looked at Sat. Nov 14 forecast for the
Nothern San Diego/LA region and the Santa Barbara region, and the wave
that day was forecast pretty accurately 2 days ahead of time on the RASP.
Alex Caldwell
CFI-G
RV-3a N1131T
RASP
One more comment about the RASP wave predictions. To forecast mountain waves the lateral grid resolution of the model must be at least four times finer than the wavelength. In practise a 1.4 km resolution does a good job in predicting wave, while at 4 km grid resolution you'll already miss lots of it. Unfortunately there are several limitations for increasing the resolution (computing time, terrain modeling, meteorological input data, etc.). Also, as Alex said, there is no rotor or other kind of turbulence prediction.
Yes, it is experimental, and it's no replacement for a proper flight preparation, and I wouldn't bet my life on it. But I've been running RASP for central Europe and Scandinavia on my server for three years now, mostly for thermal predictions, but also for some wave flying areas. When I compare my (or other peoples) GPS flight traces with the wave forecasts, the regions of lift and sink match surprisingly well.
Hendrik
PS: To keep this RV relevant ... I've ordered my preview plans yesterday.
One more comment about the RASP wave predictions. To forecast mountain waves the lateral grid resolution of the model must be at least four times finer than the wavelength. In practise a 1.4 km resolution does a good job in predicting wave, while at 4 km grid resolution you'll already miss lots of it. Unfortunately there are several limitations for increasing the resolution (computing time, terrain modeling, meteorological input data, etc.). Also, as Alex said, there is no rotor or other kind of turbulence prediction.
Yes, it is experimental, and it's no replacement for a proper flight preparation, and I wouldn't bet my life on it. But I've been running RASP for central Europe and Scandinavia on my server for three years now, mostly for thermal predictions, but also for some wave flying areas. When I compare my (or other peoples) GPS flight traces with the wave forecasts, the regions of lift and sink match surprisingly well.
Hendrik
PS: To keep this RV relevant ... I've ordered my preview plans yesterday.
the_other_dougreeves
Well Known Member
Big thumbs up for Dr. Jack and his Forecasts. Since we don't have wave here on the southern plains
we use the forecasts for thermal strength, boundary layer height, buoyancy / shear ratio (very important) and other soaring stuff. TODR
longranger
Well Known Member
Thanks Alex! Very cool. I spent the first 41 years of my life "back east" and had never seen a lenticular untill I moved to California. This particular cloud was unusual to me in that in the 13 years I've lived here, I'd never seen one south of Tehachapi before. The "Sierra wave" is usually more to east, but that day the winds were more northwesterly than usual. From the sat photo it looks like they were right down the Central Valley.
Alex Caldwell
Member
Have you ever seen this picture? It's also from a wave generated
by the Tehachapi Mountains. Only this was a fairly rare event, where
the wind was from the ESE blowing the opposite direction from Nov 14.
It was Dec. 1977, a low pressure had moved in from the west and
there was a high inland, resulting in a very tight pressure gradient
with the wind from the ESE over Bakersfield and clocked at over 100mph
on the ground. It tore up a lot of structures and caused a lot of erosion.
The picture was taken from an airplane somewhere just N. of Bakersfield
looking South. The big dust plume rose to over 3500meters. There
was no classic lenticular cloud, but you can see how a rotor forms from
the massive dust cloud it raised up. Definitely a day to stay on the ground,
but not in Bakersfield! I was working in Lancaster in the high desert that day,
it was very pleasant out there, not much wind and fairly warm, but you could
see the dust cloud on the other side of the Tehachapis.
by the Tehachapi Mountains. Only this was a fairly rare event, where
the wind was from the ESE blowing the opposite direction from Nov 14.
It was Dec. 1977, a low pressure had moved in from the west and
there was a high inland, resulting in a very tight pressure gradient
with the wind from the ESE over Bakersfield and clocked at over 100mph
on the ground. It tore up a lot of structures and caused a lot of erosion.
The picture was taken from an airplane somewhere just N. of Bakersfield
looking South. The big dust plume rose to over 3500meters. There
was no classic lenticular cloud, but you can see how a rotor forms from
the massive dust cloud it raised up. Definitely a day to stay on the ground,
but not in Bakersfield! I was working in Lancaster in the high desert that day,
it was very pleasant out there, not much wind and fairly warm, but you could
see the dust cloud on the other side of the Tehachapis.
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Garage Guy
Well Known Member
more scary cloud pictures
That Bakersfield dust wave is amazing.
Here's a link to a gallery of photos of 'morning glory' clouds that occur in the Gulf of Carpentaria, north Australia: http://www.dropbears.com/gallery/morning_glory/Morning_Glory_Wave_2001_15.htm, and the Wikpedia entry about these things: http://en.wikipedia.org/wiki/Morning_Glory_cloud. They're pretty amazing too...
--Paul
That Bakersfield dust wave is amazing.
Here's a link to a gallery of photos of 'morning glory' clouds that occur in the Gulf of Carpentaria, north Australia: http://www.dropbears.com/gallery/morning_glory/Morning_Glory_Wave_2001_15.htm, and the Wikpedia entry about these things: http://en.wikipedia.org/wiki/Morning_Glory_cloud. They're pretty amazing too...
--Paul
jjconstant
Well Known Member
Thanks Alex! Very cool. I spent .... From the sat photo it looks like they were right down the Central Valley.
In looking at the photo, I noticed that about 100NM to the WNW (around Oceano) there is something that looks like a smoke trail from a fire in a valley and it appears the winds there are from the north east, almost PARALLEL to the ridge line generating the lenticular. Typical offshore flow; wouldn't that suggest a large high pressure area to the east? I wonder if the winds at the lenticular are what are indicated by the smoke plume or if there is such a big (almost 90 degree) difference in wind direction when there's such a geographically large offshore flow?
Just trying to get my brain around something to avoid!
Jeremy
I'm not sure if I'm answering your question about winds, but I was flying around the area of that fire near San Luis Obispo on Sat. I was at 4500 and the smoke was trailing to the south west. I wish I had my camera, it looked like a perfect ribbon in the sky, it was really pretty actually.
The winds aloft were were from the east at about 5 mph and the ride was smooth. It was a little bumpy from Santa Ynez to Santa Maria where the wind speed was higher, but it smoothed out north of Santa Maria.
The winds aloft were were from the east at about 5 mph and the ride was smooth. It was a little bumpy from Santa Ynez to Santa Maria where the wind speed was higher, but it smoothed out north of Santa Maria.
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Alex Caldwell
Member
I have an archive of some of the RASP computer model forecasts for
the Southern San Joaquin Valley area that show
the surface wind prediction for that day at 1300 PST. It pretty much matches
what you are mentioning about the wind in the area where you see the smoke
being a bit more from the north and slightly easterly direction. The wind closer to the Grapevine and
Tehachapi was more from the NNW. This is pretty common from the glider flying
we've done over the years in the area. The grid in this RASP unfortunately cuts off the area where the
lenticular was located, which was just to the east of the edge of the grid.
But in the wave related forecasts, you can see there was also wave predicted
in the area south of Mt. Pinos and the Grapevine, a bit west of where the
lenticular cloud was located. The reddish colored areas are areas of predicted
wave lift.
The Valley tends to channel the wind at lower levels so it parallels the
coast range and the Sierras, so that at the very south end of the valley, near the Grapevine
and Tehachapi, it piles up and crosses from a more NW direction. You can see the winds
in the Valley were light, even though the wind out South of the Tehachapis
were 25-30kts. I used to have a friend who lived in Mojave and liked to say, "the wind
doesn't blow out here, it sucks". It's sort of like a venturi there, which is why you
have all those wind generators out there.
This was not actual measured wind, it was a forecast that came out
in the early morning of 11/14 based on data collected about 11:00pm the
evening before, and processed by the RASP program overnight for use
in the early morning. The winds are supposed to be the most accurate
thing the RASP can predict. Thermal strength and height is somewhat less
accurate. Cumulus clouds and their heights are the least accurate thing it tries
to predict, but it's still pretty good at it.
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Very common sight here in Denver. With a strong westerly wind they are often there. Makes it easy to understand why the wind carries you over the peaks eastbound but knocks you down into the face of them westbound. The wind currents can be present without the clouds. Adding moisture just makes the wind currents visible. I came over the front range eastbound from St George a month ago. The downdraft at 16600' (The MEA) was over 1500 fpm. I was unable to maintain altitude. The mountain wave is something flatlanders need to learn about before they fly through our mountains.
Precipitation is even worse than cumulus clouds, and most RASP operators don't even plot it. Nevertheless, I've used my RASP rain predictions for two years to decide in the morning whether I should take the car or the bicycle to work (15 miles each way), and I hardly ever got wet -- in southern Sweden!
Hendrik
Steve Sampson
Well Known Member
I have a slightly different perspective on wave to many of the sentiments expressed here. I learned to fly on gliders in a major UK wave area. When the wave is forming its time to get the gliders out.
Yes there is rotor, and yes it can be brutal, but most of the time in a powered aircraft if you learn what is going on you can keep clear of the rotor and use the very strong lift. In a glider you sometimes just cant avoid it if you want to make it home, and you often use it to transition into the wave. I have spent many tows on both ends of the rope.
My own rule in gliders or power is keep the speed down if anywhere near the rotor, though nicely above stall speed, so you retain control.
To this day I still often go flying if the wave is setting up. I remember an enjoyable flight in my -9a climbing 1000fpm with the power at idle.
The only real problem with the rotor is it can be hard to get back on the ground if it sets up low down over your landing site. You learn in gliders though that the rotor cant go through the ground so in the last few seconds before touchdown the turbulence reduces. If you have alternative landing sites, half a wavelength up or down wind, you can always escape the rotor that way also, with an engine.
If you learn to understand the wave system there is a lot of interesting flying to be had around it. But do take care!
Yes there is rotor, and yes it can be brutal, but most of the time in a powered aircraft if you learn what is going on you can keep clear of the rotor and use the very strong lift. In a glider you sometimes just cant avoid it if you want to make it home, and you often use it to transition into the wave. I have spent many tows on both ends of the rope.
My own rule in gliders or power is keep the speed down if anywhere near the rotor, though nicely above stall speed, so you retain control.
To this day I still often go flying if the wave is setting up. I remember an enjoyable flight in my -9a climbing 1000fpm with the power at idle.
The only real problem with the rotor is it can be hard to get back on the ground if it sets up low down over your landing site. You learn in gliders though that the rotor cant go through the ground so in the last few seconds before touchdown the turbulence reduces. If you have alternative landing sites, half a wavelength up or down wind, you can always escape the rotor that way also, with an engine.
If you learn to understand the wave system there is a lot of interesting flying to be had around it. But do take care!
