Rare Clouds found in Brazil

[Dig Gil]

These are cloud formations found in Uruguai that caught the atention of NASA, it seems:

http://info.abril.com.br/noticias/ciencia/nuvem-rara-registrada-no-uruguai-14012010-26.shl

They say that this kind of clouds may lead to tornados.

 

[Loru]

Could you provide us with more detailed translation? I'm interested in this topic

 

[Urwumpe]

Not automatically connected to tornadoes, but a possible sign of the winds needed for forming one. It is a large roll cloud.

http://en.wikipedia.org/wiki/Roll_cloud

Roll clouds are linked to micro-burst activity, which can cause tornado like damages.

But the image was taken in Uruguay...one year ago:
"Roll Cloud seen on January 25th 2009, in "Las Olas Beach" located in "Punta del Este" (Country: Uruguay, State: Maldonado)"

 

[TSPenguin]

It was also featured on APOD a few days back: http://antwrp.gsfc.nasa.gov/apod/ap100105.html

 

[tblaxland]

Not automatically connected to tornadoes

Very true. We have one of the most famous regular roll clouds up in the Gulf - the Morning Glory - and there hasn't been any tornadoes up there. We do get some crazy glider pilots though...

 

[Loru]

Looks pretty scary. Especially when you're sailing.

 

[ex-orbinaut]

http://info.abril.com.br/noticias/ciencia/nuvem-rara-registrada-no-uruguai-14012010-26.shl

Looks almost like a massive lenticular, but it is odd that it appears to be at roughly 90 degrees or so to a coast line. They are normally associated with mountain wave. Wonder what caused it? Very weird...

We do get some crazy glider pilots though...

That's pretty straightforward orographic cloud, characteristic of the Foehn effect. Saturated air gets forced up the side of the mountain, cools at the saturated adiabatic lapse rate (-1.5 C per 1000 ft). If it reaches its dew point, then you get the cloud. On the lee side of the mountain, the air descends again, and warms up at the unsaturated adiabatic lapse rate (3 C per 1000 ft), resulting normally in unusually warmer weather on the lee side than the wind side. Cool, eh?

Quito is permanently subject to this effect, sometimes with the cloud, sometimes without.

PS:
Had a better look at the footage, it is very strange. Orographic formations are normally stagnant, with the wind moving through them (as it is the temperature changes of the air travelling over uneven land that causes the condensation). These clouds appear to be in motion. Never heard of this before... spectacular.

 

[tblaxland]

Had a better look at the footage, it is very strange. Orographic formations are normally stagnant, with the wind moving through them (as it is the temperature changes of the air travelling over uneven land that causes the condensation). These clouds appear to be in motion. Never heard of this before... spectacular.

Lol, I just finished typing a rebuttal then noticed this edit The wiki article has a pretty good explanation on the formation too. There are some videos of it taken from hang-glider on this page: http://www.williamolive.com/. Recommend this one for starters: http://www.williamolive.com/videos/morning-glory-26th-09-2005.wmv

 

[Dig Gil]

I got that link from 3rd party. Never knew about such formation before, that's why I've made this thread.

For those who want to, I'll make a literal translation from Portuguese:

RARE CLOUD FORMATION RECORDED IN URUGUAY

SÃO PAULO – What looks like to be a tunnel in the sky is, in reality, a rare formations of clouds.

The picture captured by a female tourist in January at Las Olas beach, in Maldonado, Uruguay, caught so much attention that it was featured in NASA's homepage.

The photo was taken by Daniela Mirner Eberl ended up in the features of the day [side note: Picture of the day] of the American Space Agency.

NASA explains that clouds like these may be form when a storm moistens the hot air and makes it ascend next to a cold air front.

Those rolls of clouds may have air rotating in their horizontal axis and, is believed, that may transform themselves into tornadoes.

 

[RisingFury]

That's one funky lookin' cloud!

 

[DagoO]

Looks very scary..is it empty inside?

There are a lot of videos about this cloud on youtube, it's very impressive !

http://www.youtube.com/results?search_query=roll+cloud&search_type=&aq=f

 

[John_L]

If I saw that, I'd be expecting the cloud to part and the "second coming" to happen shortly thereafter... lol