Saturday, December 6, 2008

Amazing Lenticular Clouds and Weekend Weather

A weak front is now moving into the the region from the north. You can see the thickening clouds aloft...and they are evident in a recent high resolution visible satellite picture (see attached). The latest radar show some showers over the northern part of the state...they are all light (see radar image). Tomorrow a stronger system will be over us, and should produce a well-defined convergence zone (with moderate rain) over central Puget Sound. There will be showers in the mountains with snow down to 3000-4000 ft. Monday still looks dry...except for a few lingering showers in the mountains.

Yesterday, there were the most amazing wave clouds near Mt. Rainier (a sample picture is attached by Tim Thompson). KOMO TV has placed a number of the pictures online at
http://www.komonews.com/weather/blog/35631614.html

These are mountain wave clouds produced by air being forced to rise and sink by the mountain. The mountains displace the air upwards and then it goes up and down for a while. Where the air goes up..you get clouds, down clear air. These clouds often are lens shaped...and have been mistaken for flying saucers. In fact, the flying saucer craze started in 1947...and where was the first UFO seen?...Mt Rainier! I bet you can guess what it really was. I have a large section in my book on these mountain wave clouds.

5 comments:

Jon said...

I have seen mountain wave clouds before. Typically on or around the mountain and just one or two. What gives with the series of clouds and is it a standing wave?

Jim said...

Cliff,
When I lived near Orting, we would always watch Mt. Rainier to see when a cloud cap appeared. The cap looks a lot like the top of the lenticular clouds, only it sits right on the top of the mountain. Usually that was a guarantee of a change to rainfall within 24 hours. What do you call that phenomenon?

By the way, I just checked out your new book from the Pierce County library (I was the 1st). What a great text! Now I'll have to buy it, plus a few extra copies for other weather buffs I know.

The Columbus day storm discussion brings back memories. At the time we lived on Titlow Beach on the Tacoma Narrows. The afternoon of the storm my dad came home from work early, probably around 4 p.m.. He tapped the barometer on the wall, as was his custom, to see which direction the needle moved (He had been a Coast Guard skipper in Alaska during WW2). When he saw the big drop in pressure he said "Jimmy! We need to go out and bring in the garbage cans and lawn furniture because we're in for a helluva blow tonight!" We got out the candles and flashlights, too. I remember listening in the dark to the howling wind and the crashing of tree branches on the roof. What a night that was. Thanks for the memories.

Cliff Mass Weather Blog said...

Jon and Jim,
The layering of the clouds is due to the layering of atmospheric moisture..which is not uniform with height. As Jim notes, such clouds often presage a change in the weather...cliff

berd said...

Great Mount Rainier Cloud Photo!

Some Good said...

I understand lenticular clouds often mean change is coming, but I've heard some people insist worse weather is coming, and others insist stable weather is coming.

Do you believe it is one or the other, or do lenticulars only forecast change?