Tuesday, August 7, 2012

Amazing Mammatus

Announcement: Columbus Day Storm 50th Anniversary Gala at the UW: Oct. 11, 7:30 PM

On Thursday evening, October 11 at 7:30 PM, the UW will host a gathering to review and remember the 1962 Columbus Day Storm (October 12th will be the 50th anniversary).  I will discuss the major aspects of the storm and windstorm chronicler Wolf Reed will tell even more.  The Mt. Hebo radar dome broke apart that night as winds gusted above 150 mph, and we will have an eye witness account.  And there will be time for your comments, questions, or stories.  Steve Pool of KOMO TV will MC.  This meeting should be great fun will take place in Kane 120 on the UW Seattle campus.  You need to register for this if you want to go, since I expect it to fill.  To do so, go here.  The gathering is free, but the expenses are being covered by my research fund, so any contributions to offset the costs are very welcome. 
_____________________________________________

Sometimes the atmosphere produces images that leaves ones jaw agape.  Yesterday was such a day.  Many of you noticed a huge thunderstorm along the eastern slopes of the Cascades...a storm so tall (reaching roughly 35,000 ft) that it was easily visible from much of western Washingtion. (here is a picture taken by John Caldwell from Seattle.


This storm had a very large and prominent anvil, under which there was the most extraordinary field of mammatus clouds.  Here are some stunning pictures sent to me by John Stimberis of these features:








Pretty amazing pictures.   Some of you also saw some mammatus clouds on this side of the Cascades associated with the modest mid-level convection that moved over Seattle mid-day.

Why do we get these types of clouds?    They represent upside down convection...clouds that get cooler or heavier than their environment and convect downward...that is they sink!  Mammatus cloud are often associated with thunderstorm anvils. As updrafts carry precipitation-filled air to the thunderstorm top, upward momentum is lost and the air begins to spread out horizontally, becoming a part of the anvil cloud. Because of its high concentration of precipitation particles, the saturated air is heavier than the surrounding air and sinks back towards the earth. Evaporation and melting at the bottom of the cloud layer can also lead to cooling and downward convection.

Well you can't say this blog is not titillating.

No thunderstorms today on the eastern Cascade slopes...and the coming week does not look very unstable.


15 comments:

Hindu said...

Watched that cloud from Tri-Cities. Thanks for the explanation. Never knew what caused the beloved anvils.

Rod said...

Hi Cliff,

In other news, the Saturday and Sunday weather for Seafair week-end could not have been better. I was worried a bit about the breeze on Saturday, but it was quite calm on Sunday. Much to the hydroplane drivers' relief, I would imagine.

Traci said...

Thunder in Bellingham right now

natchrl8r said...

No thunderstorms? We just had a doozy in Bellingham!

Unknown said...

Thunder in Agnew this afternoon. Didn't see lightning, but it was obvious from the radio reception static it was around.

smokejumper said...

I commented last night, but that was the cell that formed right overhead.

Took notice there was virtually no other clouds 360 degrees around the storm. Ironically, I remember thinking "What does this look like a few miles away."

My station had a dewpoint of 72. Nearby WSU agmeter had a concurring 71. 100 degree valley heat, lift from the surrounding hills was enough instability for that one cell to bust through a strongly capped atmosphere. Tstorm perfection.

I made that up, but that was my explanation when people asked me about the freak isolation.

Isaac Molitch said...

"Well you can't say this blog is not titillating."

Classic, Cliff!

Lindsey said...

"mammatus" clouds . . . "titillating"

"mammatus" clouds . . . "titillating"

"mammatus" clouds . . . "titillating"

hmmm . . .

Ferdi said...

We had lots of lightening and thunder last night here in the San Juans. Most of it was cloud to cloud, but as the storm cells moved north many flashes were ground to cloud. Vancouver, BC had power outages and people were stranded for a time on Grouse Mt. due to the storm, which was also accompanied by heavy rain in some locations.

matthewcox said...

We watched this cloud brewing while sitting on our back deck in Ellensburg. It began down beyond the hills to Yakima and parked right overhead. We were surprised to read that it was seen in Seattle! Here's one one of our dozens of pictures of it that we put up on our farming blog: cloud image. You can also check out our blog if you like: http://futurefarmerslivehere.wordpress.com/

Ellie said...

This was taken in eastern Oregon May, 2008- I'd always wondered what kind of cloud it was- sounds like possibly a mammatus? https://www.facebook.com/photo.php?fbid=4479866039816&set=a.1100971409562.2017121.1384984613&type=1&relevant_count=1&ref=nf

Unknown said...

Re: 1962 Columbus Day storm. My treehouse was destroyed when the tree holding it blew down. The tree also smashed my mom's picnic table, making half the family sad & upset. I've watched the weather since then with a very personal feeling of involvement.

Buddy said...

Were those pics from john stimberis of that storm?

Absolutely stunning. Thanks for sharing Cliff and others who posted pictures.

Lindsey said...

I have heard much about the Columbus Day storm of 1962 from my family, but was not able to witness it myself, being the youngest. I was in utero, about two weeks, as it turned out, from birth.

windlover said...

I love to hear my dad tell his stories about the Columbus day storm. He was driving bus for Greyhound at the time. They were up near Bellingham and a huge gust nearly blew the bus over and blew out the windows...the passengers were having to hold the windows in place....crazy! I love a good windstorm but that one may have been a bit much...even for me!