Cloud identification?

[Patrick Boomer]

Thanks so much, Laura. I did a quick google image search for altocumulus lenticularis and several photos came up that look like these. thanks again; Mystery solved!

Cool clouds, gotta love the neat stuff the Rockies can spin up!
Looks like you may have been under the edge of a decaying lee wave, looking south or a bit southeast?
We have a nice knife-edge section of Rockies here in Alberta from the US border to the elbow that regularly sets up huge standing waves and toasty chinooks for the winter.

 

[Melanie Kern-Favilla]

Cool clouds, gotta love the neat stuff the Rockies can spin up!
Looks like you may have been under the edge of a decaying lee wave, looking south or a bit southeast?

Wow, there are some smart people on this forum. Yes! I was facing S/SE in the late evening in early July. There was some decent convection going on to the east of this system, as I recall.

Wasn't there an airplane crash in the late 80's/early 90's in Denver that was caused by these rotors? I seem to remember something like that...

I'm learning so much on this thread. I just wish I were shooting RAW at the time...argh!

Melanie

 

[Laura Duchesne]

I'm a little confused...I thought lenticularis was pretty much in the shape of a round or elliptical lens shape. They also tended to be very striated somewhat like a meso can become. Perhaps someone can point me to where it shows lenticular formations that look like Melanie's, because I might have had that all wrong.

I thought that one cloud on the left further back looked like an elongated lenticularis, it kinda has that striated look and rounded edges. Perhaps it was weakening at that point, but it's possible for me to be wrong too.

Other examples of lenticular clouds:
http://www.stormeyes.org/tornado/SkyPix/wcnpwavs.htm
http://www.stormeyes.org/tornado/SkyPix/lenticul.htm

Tom suggested rotor clouds, that makes more sense now that I think about it.

The sky is indeed amazing though!

 

[Tom Dulong]

Wasn't there an airplane crash in the late 80's/early 90's in Denver that was caused by these rotors?

Yes. There was a United Airlines B737 crash in Widefield, CO while on approach to the Colorado Springs airport in March 1991. I was forecasting from the Denver NWS office when that occurred. Wind shear associated with rotor action off of Pikes Peak combined with a suspected aircraft mechanical failure were the most likely to blame, based on the NTSB report. Twenty-five people died in the crash.

This illustrates how non-convective low level wind shear can be as deadly as the convective variety for aviation.

 

[Jim Rood]

Ah, the '07 Northlands tour. Seemed our breakdowns led to some of the best sights...Including railroad graffiti
I don't remember seeing that though.

 

[Melanie Kern-Favilla]

Ah, the '07 Northlands tour. Seemed our breakdowns led to some of the best sights...Including railroad graffiti
I don't remember seeing that though.

LOL, Jim! I was looking at that Clash photo again today. Funny stuff.

As I was looking through the photos, I discovered this photo taken a little later that evening. The clouds lost a little bit of the cylindrical appearance, but they still look similar. What an incredible sunset we had that night in Great Falls...

Mel

 

[rdale]

NASA Tech Report

Just came out today - but it's a BBBBIIIIIGGGG file.

<table bgcolor="#666666" border="0" cellpadding="3" cellspacing="1" width="100%"><tbody><tr><td align="left" bgcolor="#eeeeee" valign="top" width="27%">Title:</td> <td bgcolor="#ffffff" valign="top"> Wave Meteorology and Soaring </td> </tr> <tr> <td align="left" bgcolor="#eeeeee" valign="top" width="27%">Author(s):</td> <td align="left" bgcolor="#ffffff" valign="top"> Wiley, Scott </td> </tr> <tr> <td align="left" bgcolor="#eeeeee" valign="top" width="27%">Abstract:</td> <td align="left" bgcolor="#ffffff" valign="top"> This viewgraph document reviews some mountain wave turbulence and operational hazards while soaring. Maps, photographs, and satellite images of the meteorological phenomena are included. Additionally, photographs of aircraft that sustained mountain wave damage are provided. </td> </tr> <tr> <td align="left" bgcolor="#eeeeee" valign="top" width="25%">NASA Center:</td> <td align="left" bgcolor="#ffffff" valign="top"> Dryden Flight Research Center </td> </tr> <tr> <td align="left" bgcolor="#eeeeee" valign="top" width="27%">Publication Date:</td> <td align="left" bgcolor="#ffffff" valign="top"> August 29, 2008 </td></tr></tbody></table>
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080043828_2008040595.pdf