Mt. Rainier & Lenticular Clouds

Biff: 3rd Jun 2006 - 09:26 GMT

These are great, We have no mountains here so I've never seen this, thanks.

jack: 3rd Jun 2006 - 14:22 GMT

all three pics are great. you have given us good info on these clouds. the middle pic shows the clouds in best form. the mountain is beautiful.

EvilGentleman: 3rd Jun 2006 - 18:52 GMT

As far as I can recall from my weather observer training, ACSL (altocumulus staing lenticular) are the result of high winds aloft, and can be formed by wind passing over mountains, but they can be formed in pretty much any situation where you have very high winds at mid-level altitudes (6500 to 20,000 feet). The classic ACSL cloud looks like a cigar-shaped UFO. While much less common, I have also seen stratocumulus standing lenticular, at an altitude of 4500 feet.

High winds close to, but not at the surface, are a common event around Southampton Island in Nunavut, where I used to work doing weather observations. These winds could at times reach high speeds just 30 feet off the ground, while conditions at the surface were calm. This could sometimes make my weather observations difficult, as the cups of my amemometer (wind meter) are located at the top of a 30 foot pole. When the winds are like that, ceiling balloons become utterly useless, since they rise lazily for about 20 to 100 feet, then suddenly shoot off laterally in the direction of the wind until they are carried out of sight.

Equally irritating would be when these high winds near the suface suddenly become turbulent during winter, which would result in conditions at the surface going from dead calm to blizzard in 5 seconds. I was outside tending to my meteorological equipment when suddenly, I was enveloped in a blizzard that was so intense, I could not see my hands at the end of my outstretched arms. It stayed like that for 5 minutes or so, the reverted to absolute calm.

aer suzuki: 4th Jun 2006 - 02:21 GMT

Thanks to all for the replies, it's appreciated.

EvilGentleman : Weather is very strange. Seems you've had an interesting life judging by your photos and comments. Thanks for the information. Do you know why these particular lenticulars would be round? I'm assuming the mountaintop sends the wind into a swirl, or something like that, but I really don't know. Or if the wind comes bouncing off the top of the mountain, it could be sort of "blowing bubbles"...err...that's why I never talk about the weather, I'm ignorant about it.

EvilGentleman: 4th Jun 2006 - 08:33 GMT

I am surprised at how much of my weather training has been forgotten in the seven years since I last worked at the weather station. I guess that is why they made us work a minimum of one shift every 30 days in order to keep our certification up-to-date. I remember when I went on my trip to the eastern US in 1999, I had to work from midnight till 8 AM on August 1st, then I caught a flight out of the Arctic later that day and started making my way to Montreal (from Winnipeg by Greyhound bus) to meet up with my prospective girlfriend (now my wife of 5 years). From there we headed off to Florida by car (the best way to travel, when you have young kids). Thirty states and several weeks later, we returned, and I had to Greyhound back from Montreal to Winnipeg, to catch my flight home. My plane landed at the Coral Harbour, Nunavut airport, and I quickly ran into the weather station to punch in for the 4 PM to midnight shift on August 31. Had my plane been delayed an hour, I would have lost my certification. That was as close as I could cut it, and I barely made it. That 12,000 mile commute to work was one of the most interesting months of my life.

Sorry, that was not what you asked me. I guess I'm practicing for when I become senile in another 30 or 40 years time.

From what I can recall from my training, "lenticular" means "lens-shaped", like how a magnifying glass lens looks when viewed from the side. The fact that these particular clouds are rounder probably has more to do with how long the wind has been molding their shape, and very little to do with the presence of the mountains. I strongly suspect that if the winds continued working on these clouds, they probably assumed the familiar cigar-shape a few hours after you took these pictures. Actually, it looks like they are already elongating in the third picture. The mountains may very well have contibuted greatly to the wind speed in this case, but they are not at all necessary for the forming of lenticular clouds. Lenticular clouds can happen any time you have layer-type clouds in a windy environment.

aer suzuki: 5th Jun 2006 - 09:37 GMT

Evil Gentleman : That sounds like an adventure, or maybe it's just every time I hear or read the words "Greyhound Bus" I think of an adventure...anyway.

Yeah, lenticular does refer to something lens-shaped. Thanks for the helpful info, from what I'd read so far I'd gotten the impression mountains or other huge wrinkles of land had to be involved.

I'd originally meant to post a link to a very cool photo of lenticular clouds, but forgot. So :

antwrp.gsfc.nasa.gov/apod/ap030326.html