We were driving near our house yesterday early evening, and while at a stop light, I was able to take this picture.



About six hours later, we had strong storms, tons of rain, lightning, etc.

I bet I probably have an extra two or 3 inches of water in the pool this morning. Does anybody know what this club formation is as I’ve never seen anything like it before?

Screen grab from "Revelation: The End of Days" showing Jesus' second coming...slightly spooky. Revelation 1:7

Cumulonimbus. A.k.a. a supercell. (Mesocyclone.)
This according to my son who is a weather bug.

quote:

Originally posted by pace40:
Screen grab from "Revelation: The End of Days" showing Jesus' second coming...slightly spooky. Revelation 1:7

If that was yesterday, seems to be a lead up to horrible weather last night into today, at least here on the Illinois side of the river. Tons of rain, pretty big hail and about as much lightning as I can remember. A weird last half day.

I'm no expert, but I've seen enough movies to know that in about 6 seconds the spaceship from "Independence Day" is gonna appear.

It’s a super cell.

We see them with some frequency out here on the western plains, in fact, I just took a picture of one the other day at sunset that’s kinda pretty. I would post it now, but it would be too big; I have to resize it on our desktop.

Those super cells are bad medicine on a wildland fire because the winds tend to flow out in all directions. They can carry hail and heavy rain at maturity.

Ripley, the pic was taken yesterday at 6 pm.

The storm hit around midnight and kept waking up my dog Ollie and I all night. Hail, lightning, tons of rain, etc.

Hard keeping my eyes open at work today.

Way back, when I was a student pilot, my instructor told me to avoid the nympho-cumulus.

I asked what he meant, and he said "Don't fly in the fucking clouds."

It's a cumulonimbus, aka thunderstorm, which has topped out into a different layer. Sun hitting it from a low angle makes for a spectacular scene.

Warm air rises, which is why thunderstorms prevail in hot sunny conditions. The sun heats the earth's surface which heats the air at the surface, and columns of hot air start rising. The air cools as it rises, reaching the point where the vapor condenses out to liquid water, and it becomes a visible cloud. The condensation process warms the air, which increases its upward rise. Air inside the cloud moves upwards primarily.

The atmosphere naturally gets cooler as altitude increases. If it gets a lot cooler faster, it is unstable air. Think of summer with air near the surface getting warmed up, so the air aloft is a lot cooler than surface air, and it is unstable. (Contrast that with winter, where the surface is cold and thus air aloft isn't much cooler, and is thus stable, resulting in a cloud layer not vertical cumulonimbus).

So this rising humid warm air starts condensing, getting warmer, and rising into cooler air in an unstable air mass. So it keeps rising, more vapor condenses out, warms the air, and it keeps going up.

That's how a thunder storm cloud is built.

Eventually most of the moisture has condensed out, the air has risen up high enough that it is well below freezing, and the surrounding air is no longer colder than the cloud. At very high altitudes, above about 30,000 ft, the air doesn't get much cooler by going higher, so the propensity of a cloud to grow upwards is much less. So the air in the cloud stops rising. That is the top of the cloud.

Sometimes, as in the picture above, the cloud rises into a substantially different layer. Usually very stable, sometimes with a strong windspeed. The upwards moving air hits that layer and can't penetrate up, but has enough momentum to spread out sideways. Sort of like smoke rising up to a ceiling and spreading sideways.

quote:

Originally posted by V-Tail:
Way back, when I was a student pilot, my instructor told me to avoid the nympho-cumulus.

I asked what he meant, and he said "Don't fly in the fucking clouds."

Thanks for all the details Flysig.

Originally, I was wondering if there was going to be a special event as alluded to by both pace40 and 12131.

quote:

Originally posted by h2oys:
I was wondering if there was going to be a special event as alluded to by both pace40 and 12131.

I'll tell you what. I'm glad I didn't see that with a full bladder.

Here's the photo I mentioned above. A week or less since I took it.

quote:

Originally posted by h2oys:
Ripley, the pic was taken yesterday at 6 pm.

The storm hit around midnight and kept waking up my dog Ollie and I all night. Hail, lightning, tons of rain, etc.

Hard keeping my eyes open at work today.

Thanks h2oys, I saw the pic and StL location and started typing without reading your info.

Midnight here as well and the lightning was unbelievable. Across the whole horizon, all directions and constant activity for ten or more minutes. Nothing directly on top of us but I had to wait a while before hitting the sack.

quote:

Originally posted by TMats:
Here's the photo I mentioned above. A week or less since I took it.

Neat Pic and thanks for sharing!

Several years ago, a supercell nailed our area causing wind, hail, and flooding damage to most of the homes. I remember as it was coming, I thought it strange there was non-stop thundering. I will post image here if I can find it.

I would have been expecting the thousand mile an hour shock wave in a few seconds.....

Just a massive thunder head building up.. you know what the outcome was....

The prognosticators don't want to tell you this but these have been going on here for about 2 billion years....

I believe the scientific name is "mothership"

My lightning tracker had the South County/Jefferson County areas hit with over 1200 flashes. Heck of a light show.