Cloud question

flhrci

flhrci

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David
So, what causes clouds to line up like this? They were all in lines.

IMG_0119.JPG


David
 
"Gravity waves." Displace a parcel of air up in stable air and it will bounce up and down for some time. If it happens to be saturated, it will form a cloud at the top. The displacement can come from terrain, thermal, or airmass features. Unless it is continuously formed (such as wind blowing over a ridge), it will move with the wind.
 
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MAKG1 said:
"Gravity waves." Displace a parcel of air up in stable air and it will bounce up and down for some time. If it happens to be saturated, it will form a cloud at the top. The displacement can come from terrain or airmass features.
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Makes sense. Thanks!

David
 
often cumulus clouds will line up with the wind. we call them cloud streets and they are the stuff dreams are made of for glider pilots. i'm guessing a cold front passed the night before?
 
tonycondon said:
often cumulus clouds will line up with the wind. we call them cloud streets and they are the stuff dreams are made of for glider pilots. i'm guessing a cold front passed the night before?
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I remember 'cloud streets' from a thread awhile back. Cool stuff

Are those clouds pictured the ones that form in the rotor?
 
Those aren't mountain waves. Different scale.

Columbus has terrain features that can make small scale behaviors like that. For instance, differential heating off the Lake Erie shore (those waves can persist for hundreds of miles). A row of moraines with a stiff stable wind could do it as well.

I certainly agree that different layers moving against one another could cause this as well.
 
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tonycondon said:
often cumulus clouds will line up with the wind. we call them cloud streets and they are the stuff dreams are made of for glider pilots. i'm guessing a cold front passed the night before?
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Indeed

They are aligned (parallel ) with the wind. They are not from mountain waves where any cloud alignment would be perpendicular to the wind.

Not really answering your question because sometimes cumulus line up nd sometimes they don't. It's due to a combination of factors I've never full understood except to say it happens a lot right after a cold front passage.

I'm in Phillie right now and we have some streeting here too. It would not be unusual for there to be signs of mountain wave later today as the sun goes down, surface heating stops and the atmosphere become more stable. The Appalachians often form mountain waves for many mile downwind. I've been thinking about spring time soaring all day today... A real strong day :)
 
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Bill Watson said:
Indeed

They are aligned (parallel ) with the wind. They are not from mountain waves where any cloud alignment would be perpendicular to the wind.

I'm in Phillie right now and we have some streeting here too. It would not be unusual for there to be signs of mountain wave later today as the sun goes down, surface heating stops and the atmosphere become more stable. The Appalachians often form mountain waves for many mile downwind. I've been thinking about spring time soaring all day today... A real strong day :)
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there were pretty classic looking post-frontal conditions in Iowa yesterday and monday. i'm actually really surprised that my 1-26 downwind dash friend from the MSP area didn't head for Indiana.
 
Clouds aren't actually "things". It is just a condition of the air mass that causes the moisture, which is always present, to become visible. Watch time-lapse films of clouds over mountains and you can see that although the air mass is flowing the clouds form at a stationary position. They aren't composed of the same vapor particles throughout there existence but of transient vapor particles that become visible as they pass through the specific area, move past and become invisible once again.
 
Silvaire said:
Clouds aren't actually "things". It is just a condition of the air mass that causes the moisture, which is always present, to become visible. Watch time-lapse films of clouds over mountains and you can see that although the air mass is flowing the clouds form at a stationary position. They aren't composed of the same vapor particles throughout there existence but of transient vapor particles that become visible as they pass through the specific area, move past and become invisible once again.
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that is true when the creative mechanism is geography based. most of the time with cu, the cloud is moving with the air mass.
 
Cloud fan here. Maybe you already know ... there is a famous cloud "street" called the Morning Glory that rolls inland across a section of Australia periodically, moving at about 35 mph. It's not entirely predictable, but enough so that pilots hang around waiting for it so they can "surf" it.

http://www.youtube.com/watch?v=474Ra2DSgvM
 
Yea there was a guy last year I think who flew his sailplane over 100 miles off shore on the Morning Glory. It was a motorglider, but still!!
 
Becky said:
Cloud fan here. Maybe you already know ... there is a famous cloud "street" called the Morning Glory that rolls inland across a section of Australia periodically, moving at about 35 mph. It's not entirely predictable, but enough so that pilots hang around waiting for it so they can "surf" it.

http://www.youtube.com/watch?v=474Ra2DSgvM
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Thanks for posting that! Very neat!

David
 
MAKG1 said:
Off shore in a sailplane? That sounds like a really bad idea.
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He had a motor that probably could've gotten him back to land if the lift quit. if the motor started of course :) This guy is pretty experienced XC pilot and had done a lot of morning glory flying so i figured he knew what he was doing
 
I just always assumed the clouds only formed on victor airways and left everything else clear.
 
scottd said:
David,

What day and time was this? In Columbus?
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Well, this is a little embarrassing but I forgot I had the picture. Found it the other day and forgot I had wanted to ask about it.

Anyways, the time date stamp is March 26, 2012, 11:07AM EST.

David
 
damn that was at 11 AM? glider pilots dream!
 
Becky said:
Cloud fan here. Maybe you already know ... there is a famous cloud "street" called the Morning Glory that rolls inland across a section of Australia periodically, moving at about 35 mph. It's not entirely predictable, but enough so that pilots hang around waiting for it so they can "surf" it.

http://www.youtube.com/watch?v=474Ra2DSgvM
Click to expand...
Very cool! Thanks
 
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