Strange Weather - Gravity Wave

hey people check this cool unusual weather system out
apparently a gravity wave according to the title

www.liveleak.com...

That was amazing!
Great, now I can get sea sick on land ... whats next?

reply to post by fleetlord


i saw something similar when i went to visit the grand canyon from the bus ride in Arizona desert which looked like the sky was literally swirling but that could just be a desert illusion

reply to post by madmax8


Pretty impressive. It still can be natural phenomenon. Is there some high riff or chain of mountains at direction from which wind is coming? That can explain the "parallel to camera axis" pattern. It will be helpful to know exact location and direction of view of camera.

BTW I'm still not sure, if this image is just error or what? Other images and discussion with ATS CT Police officer you can found in this ATS thread.

nothing strange, this occurs quite frequently around the globe and has done so for ever.

heavier or more dense particles in a layer of the atmosphere try to sink, and dip into a layer of the atmosphere where they are less dense and rebound upward, osscilating until equilibrium is reached. its akin to a rubber ball bouncing on a table.

-wx

Nevermind.....



[edit on 12/4/2009 by jkrog08]

reply to post by zeddissad


the image you linked is an example of two things in satellite meteorology. first, is thresholding.

the infrared images base colors on the temperatures of the object imaged, normally in a grey scale with coldest being brightest, sometimes it is helpful to apply colors to certain temperature thresholds to outline important elements of the image that would be lost in normal greyscale imagery.

the other is called foreshortening, where the resolution decreses near the edge of an image due to angle of incident energy. it causes erronius imagery near the periphial of the sat pic.

-wx

Dude, I would love to learn to surf that thing !!!

In the immortal words of Jeff Spicoli, "All I need are some tasty waves, a cool buzz, and I'm fine."

Bring on the gravity waves.

[edit on 4-12-2009 by polychronopolis]

reply to post by jkrog08


it IS a gravity wave. a common occurence in meteorology,or any fluid dynamics where there are unsimilar density values in a fluid system.

this is not referring to EM propogation, but rather the physical density and thus more weight in a particular layer of the atmosphere.

Gravity waves can be deceivingly damaging storms. One came through Alabama (USA) in April with 60mph winds (almost 100km/h) for about two hours (over 100 minutes, lol). Which is basically a category 1 hurricane with no advanced warning. I'm pretty sure it was the states most costly storm of the year so far too.

If you want to learn what exactly a gravity wave is click here: LINK





[edit on 4-12-2009 by beaverg]

reply to post by wx4caster

this is not referring to EM propogation, but rather the physical density and thus more weight in a particular layer of the atmosphere.

Oh I see, lol I thought he was talking about propagation of gravity (as in astrophysics, physics, cosmology, etc)....Nevermind, dang that term is a little misleading to those not trained in meteorology.

Thanks for clearing that up...

Originally posted by beaverg
Gravity waves can be deceivingly damaging storms. One came through Alabama in April with 60mph winds (almost 100km/h) for about two hours. Which is basically a category 1 hurricane with no advanced warning. I'm pretty sure it was the states most costly storm of the year so far too.

If you want to learn what exactly a gravity wave is click here: LINK

there are several things wrong with the information in your link.

first it describes what happens when a mesoscale high develops just rearward of thunderstorms and can be seen in a phenomenon known as a line echo wind profile, where the low level jet or rearward flanking jet of a thunderstorm is placed on the surface due to interaction between the forward downburst and the updraft of a storm, usually near the end of the life cycle as there becomes more down than upward flow.

second it describes thunderstorms in stable atmosphere. thunderstorms or convective activity is found in unstable atmospheric condtions, gravity waves are (as they said) found in STABLE atmospheres.

and as far as your post, 60 mph winds are only tropical storm force winds. a category one hurricane is 64+kts or 78mph. just getting specific there.

reply to post by wx4caster


Punctuation is your friend my friend.

To be honest, I assumed that there was something wrong with the information and expected someone to question it. It came from Alabama, after all.

As far as the science, I'm not familiar with it all so your terms like "line echo wind profile" and "forward downburst" go right over my head, intentionally maybe? Like seriously, made no sense in layman's terms. But that's cool, it doesn't sound like you were making stuff up, lol.

reply to post by beaverg


oh... sorry, i did not mean to go over anyones head, i assumed and that was wrong on my part.

let me further describe what is going on.

first a stable atmosphere is one that ismost simply described as layered with the most dense on the bottom and less dense on the top. this means that if any layer or part of the atmosphere is moved up or down it will return to its original position.

an unstable atmosphere is most simply described as one that has the most dense above and less dense below, and that means that it wants to correct itself and the less dense will continue to rise until it reaches a state of equilibrium.

this is why we have thos big ol tall thunderclouds in an unstable atmosphere. large pockets of warmer and less dense air rise, condensing, but remaining less dense through a latent heat process and can reach altitudes of over 50k feet.

a LEWP or line echo wind profile describes a category of radar returns that can be indicitive of strong straight line winds, and these can often be mistaken for tornadoes and the likes.

take this picture for example. the purple winds that are described as cold down draft are (in the case that i am describing) coming from say 850mb or about 5k feet or so. the winds here are (normally) above the friction layer, and in the cast of most frontal systems producing thunderstorms these winds are part of the warm belt of fast moving air that you may have heard described as a low level jet. this is not the only case that this can happen but is merely one example.

as the line of thunderstorms develop ahead of the cold front, you get an area of higher pressure right behind the storms. this mesohigh (as it is called) interacting with the downdraft of a thunderstorm can on occasion produce a gear like mechanism that can create an unobstructed path for the winds associated with the llj to plummet to the ground, maintaining thier speeds, ahead of or right at the storm. this is not the same as the regular gustfront, but can cause large amounts of wind damage. on radar this phenomenon is depicted as a weaker return behind a "bowing" linear storm return, and is not unsimilar to what is called a "bow echo".

for gravity waves. imagine if you will a big bowl of oil and water that sets separated on a table. neither layer wants to move because they are less dense on tp and more dense below. now imagine that you pick up this bowl off the table by say... a half inch and drop it back on the table. the fall will cause the top layer to have a ripple effect and oscellate up and downward until all the energy caused by the gravitaional effect on the layer is either disipated or another outside factor is introduced.

this can be seen with layers of air being propogated over shallow anticyclones or mountains and the like, and is common in stable atmosphere leeward of mounatins.

hope that helps.