Page 1 of 1

Pyrocumulus!!

Posted: Sat Apr 30, 2005 10:58 am
by PurdueWx80
Bet most of you have never seen this before!

Image

As far as I know, these are pretty common during the western fire season (can sometimes actually produce thunderstorms with lightning and tornado-like vortices) - I've never heard of them in the Midwest though.

BTW, I got the pic from the Milwaukee NWS site.

Posted: Sat Apr 30, 2005 2:16 pm
by Amanzi
Great pic! Kinda scary looking, its amazing that they can produce lightning!

Posted: Sat Apr 30, 2005 2:21 pm
by Stormsfury
Amanzi wrote:Great pic! Kinda scary looking, its amazing that they can produce lightning!


The heat from the fire forces air to rise, and thusly condense (if there's enough moisture, believe it or not) for the Pyrocumulus cloud to condense. The wildfires in Florida several years ago produced enough rising motion to produce sporadic intense thunderstorms from Pyrocumulus clouds. Lightning, of course, set off new fires, but luckily where it did rain, the storm produced a LOT of it.

Not so in the Western States with T-storm activity usually being the "dry" variety. Unfortunately, a lot of lightning, and very little rain.

SF

Posted: Sat Apr 30, 2005 11:18 pm
by Huckster
I have seen one pyrocumulus when I was younger. If I remember correctly, it was actually caused be a large column of smoke at one of the chemical plants down here on LA highway 1. I've made that trip down highway 1 so many times that it's just ridiculous, and the refineries/plants are always spewing huge amounts of smoke, but only once have I seen anything like that. We don't get a whole lot of forest fires and such in southeast or south central Louisiana, so to see a pyrocumulus coming off a man made, "articificial" column of smoke around here must be an extreme rarity.

Posted: Sun May 01, 2005 12:03 pm
by Windy
Stormsfury wrote:
Amanzi wrote:Great pic! Kinda scary looking, its amazing that they can produce lightning!


The heat from the fire forces air to rise, and thusly condense (if there's enough moisture, believe it or not) for the Pyrocumulus cloud to condense. The wildfires in Florida several years ago produced enough rising motion to produce sporadic intense thunderstorms from Pyrocumulus clouds. Lightning, of course, set off new fires, but luckily where it did rain, the storm produced a LOT of it.

Not so in the Western States with T-storm activity usually being the "dry" variety. Unfortunately, a lot of lightning, and very little rain.

SF


On a day with a strong cap, this certainly could be a way to break it!

Posted: Sun May 01, 2005 12:17 pm
by PurdueWx80
Windy wrote:On a day with a strong cap, this certainly could be a way to break it!


This is gonna sound really lame, but I often daydream of doing something on a mass scale to create enough heat to break the cap - when it is otherwise not quite unstable enough. I would never start a huge fire, but the thought is intriuging (I'd also consider having everyone turn on their heat and open their doors to see if that would do it). I told you this was gonna sound lame! What can I say, I'm a weather dork.

Posted: Mon May 02, 2005 5:31 pm
by wx247
That is an awesome pic.

And yes, you are a weather dork, but so are lots of us. We sympathize. :lol: