blues deville Posted January 5, 2011 Share Posted January 5, 2011 Here's one for our resident experts. Has anyone ever noticed what the wind speed is when you have encountered light or sometimes moderate turbulence when clear of any clouds? After 23+ years of flying some kind of glass cockpit jet (A320, B757, B767, B777) with digital wind displays, there always seems to be rough air when the wind is 60 kts +/- 5 or at 100 kts +/- 5. It'll generally smooth out when you get away from these speed ranges but 99% of the time its bumpy until you do. Does anyone have an explanation as to what the wind does at these two wind speeds? Thanks.bd Link to comment Share on other sites More sharing options...
SkyBlazer Posted January 5, 2011 Share Posted January 5, 2011 Here's one for our resident experts. Has anyone ever noticed what the wind speed is when you have encountered light or sometimes moderate turbulence when clear of any clouds? After 23+ years of flying some kind of glass cockpit jet (A320, B757, B767, B777) with digital wind displays, there always seems to be rough air when the wind is 60 kts +/- 5 or at 100 kts +/- 5. It'll generally smooth out when you get away from these speed ranges but 99% of the time its bumpy until you do. Does anyone have an explanation as to what the wind does at these two wind speeds? Thanks.bdCould it just be that coincidentally those are around the speeds that occur at the entry and exit points of the jetstream?I always find its bumpy on the edges just as a river experiences turbulent water along the shoreline.(transition with non moving object- or in the case of a jetstream the area of transition between fast and slow moving air.)my 2 cents ... and Im certainly no resident expert.SB Link to comment Share on other sites More sharing options...
blues deville Posted January 5, 2011 Author Share Posted January 5, 2011 Perhaps SB but what causes the turbulence to subside below 55 and above 65? The same at 95 and 105. I will attach two photos. Both over the Pacific recently and clear of cloud. One display reads 94 kts and it was light turb. As soon as the wind increased above 105 it was smooth again. I have seen this many, many times and its always the same. The second photo is crossing a north-south jet and not even a ripple at 226 kts. Link to comment Share on other sites More sharing options...
Spinnaker Posted January 5, 2011 Share Posted January 5, 2011 Interesting...paging Vsplat or Don Hudson... Link to comment Share on other sites More sharing options...
inchman Posted January 5, 2011 Share Posted January 5, 2011 Perhaps SB but what causes the turbulence to subside below 55 and above 65? The same at 95 and 105. I will attach two photos. Both over the Pacific recently and clear of cloud. One display reads 94 kts and it was light turb. As soon as the wind increased above 105 it was smooth again. I have seen this many, many times and its always the same. The second photo is crossing a north-south jet and not even a ripple at 226 kts.Based on this, I'd say that turbulence occurs more in a tailwind than in a crosswind! Link to comment Share on other sites More sharing options...
J.O. Posted January 5, 2011 Share Posted January 5, 2011 One of the roughest rides I've ever had at altitude was on a day when the strongest wind we saw was 35 kts and the average wind speed was in the low 20s. It was bad from FL250 to FL430 from Delaware all the way to San Juan. Shook loose a couple of old fillings that day. Link to comment Share on other sites More sharing options...
blues deville Posted January 6, 2011 Author Share Posted January 6, 2011 As JO mentioned there are unusual weather days. So with that in mind here is a suggestion. Over the next few weeks make a note of your wind vs. turbulence conditions and report back with your findings. If you see a wind in the 60 or 100 knot range, watch what happens as the speed changes if you encounter some turbulence.When I have witnessed these turbulence conditions in the past and mentioned it to my fellow pilots, the response has always been the same...."never noticed that before". bd Link to comment Share on other sites More sharing options...
JL Posted January 6, 2011 Share Posted January 6, 2011 Perhaps some clues lie within this discussion on bore waves, gravity waves and internal gravity waves. I thought I had heard everything about weather over the past 25 years and then this phenomenon popped up last year during the AC190 upset. Interesting stuff indeed.http://en.wikipedia.org/wiki/Gravity_wavePerhaps there is a harmonic or resonance with this motion of the upper atmosphere that is coincidental with the speeds of 60 and 100. Link to comment Share on other sites More sharing options...
blues deville Posted January 6, 2011 Author Share Posted January 6, 2011 Perhaps some clues lie within this discussion on bore waves, gravity waves and internal gravity waves. I thought I had heard everything about weather over the past 25 years and then this phenomenon popped up last year during the AC190 upset. Interesting stuff indeed.http://en.wikipedia.org/wiki/Gravity_wavePerhaps there is a harmonic or resonance with this motion of the upper atmosphere that is coincidental with the speeds of 60 and 100.Interesting thought JL. I have been curious if perhaps the condition I am describing is some kind of wind resonance thing. However, my experiences with this do not involve any cloud formations, wake turbulance or mountain wave.Note: Your link is not working for some reason. Link to comment Share on other sites More sharing options...
JL Posted January 6, 2011 Share Posted January 6, 2011 Sorry about that. Here it is again...Gravity Waves Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.