What type of cloud can spawn a tornado

It was highly structured, evolving right before my eyes over the course of a few minutes, from a distinct narrow funnel hanging from the cloud base then fattening into a thick straight-sided cylinder. It was incompletely connected to the cloud base above it. It was rotating fairly rapidly—no time lapse needed in order to see this—but certainly not as fast as a tornado. It eventually began to breakup, stopped rotating, and turned into ordinary low-hanging scud.

The weather system it was associated with was not conducive to producing tornadoes. Clouds were a moderate collection of cumulus, some thick and dark, most light and fluffy, that had produced a few showers as they moved north. The system simply did not have the strength, density, size, nor organization necessary for a true tornado.

The landscape is a wide flat valley between mountain ranges the Central Valley of California , and the day was very warm and humid. This system never did develop into a real storm.

The time was early afternoon, right about the time when summer temps start to get hot. This cloud puzzles me because it certainly was not a tornado, nor even the threat of one, but it had definite bounded structure and rotated, so it was not entirely scud either. Is there some kind of weird hybrid? I saw one of those things you were talking about right over my neighborhood in Pennsylvania, and it formed gust as quickly pun intended. It was shaped like a giant can of canned tomato sauce, with extra can, but shorter ish.

Some lightning was coming out of it and going back into it, lighting MY strange, rotating cloud up. My phone was able to record it, but I took so many other picture and videos that I think I had to delete it. I forget the exact date and time, but I think it was last year. I then looked at this comment and found that I am not the only one who saw a cloud like the one I found. This sounds like the stereotypical wall cloud. A google search can confirm this though. I take many pics of clouds, one of my favorite past times.

I often see the Tail Clouds and did think that they are makings of a tornado. I live in central California and do not experience being in fear of tornados, but you never know, right!?! I look forward to reading more articles by you Amber Kanuckel.

This article and photos were so good I figured Jaime was the author till I got to the bottom. Thanks Amber, you knocked it out of the park! It is my understanding that in order to be a tornado, it must touch the ground. Since I grew up in one of the Tornado Alleys, I do have a question.

I always had the understanding that tornadoes can set down on the ground and travel a ways, lift up as the storm moves along and then set back down. The article gives to understand that it is not truly a tornado if it is not making contact with the ground.

I wonder…??? So the storm can have…tornado, yes…tornado, no…tornado, yes…tornado, no…??? With the exception of this question, it was a very informative article. While one is easily mistaken for the other to the untrained eye, cloud spotters know that a shelf cloud is associated with thunderstorm outflow not inflow like wall clouds and can be found in the storm's precipitation area not rain-free area like walls clouds.

Another hack to telling a shelf cloud and wall cloud apart is to think of rain "sitting" on the shelf and a tornado funnel "coming down" from the wall. One of the most feared and easily recognized storm clouds is the funnel cloud. Produced when a rotating column of air condenses , funnel clouds are the visible part of tornadoes that extend downward from the parent thunderstorm cloud.

But remember, not until the funnel reaches the ground or "touches down" is it called a tornado. Scud clouds aren't dangerous clouds in and of themselves, but because they form when warm air from outside of a thunderstorm is lifted up by its updraft, seeing scud clouds is a good indication that a cumulonimbus cloud and hence, a thunderstorm is nearby. Their low height above ground, ragged appearance, and presence beneath cumulonimbus and nimbostratus clouds mean scud clouds are often mistaken for funnel clouds.

But there's one way to tell the two apart -—look for rotation. Scud do move when caught in the outflow downdraft or inflow updraft regions but that motion typically isn't rotation. Roll or arcus clouds are tube-shaped clouds that literally look like they've been rolled up into a horizontal band across the sky. They appear low in the sky and are one of the few severe weather clouds that are actually detached from the storm cloud base.

This is one trick for telling them apart from shelf clouds. Spotting one is rare, but will tell you where a thunderstorm's gust front or another weather boundary, like cold fronts or sea breezes lay, since these clouds are formed by outflows of cold air.

Those in aviation may recognize roll clouds by another name — "Morning Glorys". Wave, or Kelvin-Helmholtz clouds, resemble breaking ocean waves in the sky. Wave clouds are created when air is stable and winds at the top of a cloud layer are moving faster across it than those below it, causing the top clouds to be whipped around in a downward curling motion after hitting the stable layer of air above.

While wave clouds aren't related to storms, they are a visual cue for aviators that a large amount of vertical wind shear and turbulence are in the area. Asperitas are another cloud type that resembles a roughened sea surface. They appear as if you were underwater looking upward toward the surface when the sea is particularly roughened and chaotic.

Although they look like dark and storm-like doomsday clouds, asperitas tend to develop after convective thunderstorm activity has developed. Much is still unknown about this cloud type, as it is the newest species to be added to the World Meteorological Organization's International Cloud Atlas in over 50 years.

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Pyrocumulonimbus clouds also occasionally trigger fire tornadoes , which form when the updraft twists and stretches the air that is being sucked into the sky at high speeds. These fiery whirls tend to last only a few minutes and reach no more than feet tall.

But with wind speeds of up to miles an hour , they can do serious damage to anything in their path. Fire weather helped fuel some of the devastating wildfires in recent history. In , an even bigger wildfire in the forests of British Columbia produced five fire thunderstorms nearly simultaneously.

Multiple studies have shown that the plumes were comparable to those of a moderate volcanic eruption and remained in the atmosphere for almost nine months. In the United States, California has also seen several intense pyrocumulonimbus events. During the Carr fire near Redding in July , a fire tornado spinning at speeds of up to miles an hour was responsible for four of the eight deaths associated with the fire. In August , several possible fire tornadoes were reported in Northern California during a record-breaking fire season rife with firestorms.

Firestorms also contribute to the damaging effects that wildfires have on human health. The gases and particles that make up wildfire smoke have been linked to respiratory and cardiovascular illnesses, and firestorms can exacerbate the blazes and increase levels of smoke. As climate change stokes bigger and more intense wildfires , scientists believe the planet will experience a rise in firestorms.

In , Australia saw as many fire-generated storms as it had seen in the 20 preceding years. On September 7, , smoke from a pyrocumulous cloud near Fresno, California, shot 10 miles into the stratosphere, a record for a fire in North America that likely released significant carbon emissions.

Answering these questions will be key to understanding the true consequences of firestorms in a warming world. All rights reserved. How firestorms get started Firestorms form through a convective process , in which heat rises through the air. Share Tweet Email. Read This Next Wild parakeets have taken a liking to London.

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