Why do tornadoes (seem to) form very near the edge of a stormcloud?

Nearly all photos and/or videos I've seen of a tornado shows clearing sky or clear sky immediately behind it. So it is mostly at storm's edge.

Why is that?

Thanks in advance for any replies.

Nadme. OK I'll venture. I used to show the video"Storm Chasers", a Nova special, with the first teams that used TOTO, the TOwable Tornado Observatory, ...caused Hollywood to make Twister with Helen Hunt.

Tornados form from cold fronts. Cold dense air plows across the ground, pushing warm, less dense air up over the "plow". The rapidly rising warm air cools when it goes aloft, releasing heat as the moisture condenses. The heat reenergizes the updraft, and it grows stronger....cumulonimbus cloud. The opacity drops and it grows dark and gloomy below. The upwelling finally stops, and the air begins a descent. Winds produces twisting patterns, as updrafts meet down....mesocyclones. The instability develops when a large mass of cool dense air spills forward over the "plow". Now it's a huge dense mass of cold air poised above less dense warm air below....and it isn't plowing. It plummets towards the ground, like water draining out of a tub, spinning as it goes. If it finds a mesocyclone to make an easier path, it follows that, and a twister can appear fairly quickly. Big ones require a large temperature difference in front of and behind the cold front , and the instability is greatly enhanced by flat terrain...hence Kansas, Texas, Oklahoma, Ohio...but my home state of Massachusetts is not immune.
The area behind the front can also see tornados, and multiple funnels are not uncommon...the behind tornado seems to be in "clear" air, but it's still unstable. The updrafts can be very violent, as can the downdrafts.
I will never forget the student pilot who flew out of East Taunton Airport in 1970, and made the mistake of not checking the weather. Once airborne, he turned West into a thunderstorm with extremely violent updrafts. The people in the terminal heard his pleas and screams for help for ~ 15 minutes as the storm took complete control of his plane, disorienting him, and bringing him to dangerous altitudes. Finally he managed to escape it's winds, and he made an emergency landing, abandoning his plane on the runway...and walking to his car, covered in body fluids...all of them. We never saw him again.
While watching a tornado on TV can be fun, the debris in the funnel cloud can do lethal damage to you...the movie showed a 2 X 4 go through a brick wall, and a 1 inch steel safety room is not uncommon, or a storm cellar in the midwest. Even common straw can penetrate wood several inches at high velocity.. ciao pete

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Some of it's a real phenomenon, because tornadoes form most easily where there's a downdraft and rear-flank downdrafts tend to be more common and powerful. But there's also some photographic bias; tornadoes fitting the description you gave are more likely to be photographed because they're the more likely to be highly visible and tend to look cooler.

Trinitree88: Yikes!! I wonder if he ever got into another airplane again.

Delvo: Hmmmm, I hadn't considered that. But again...it seems often seen on video clips too (amateur from 1990s and further back).

The most impressive video I've yet seen of tornadoes was an outbreak in Texas, sometime in the late 1980s IIRC. These people had stopped along a state highway and slowly panned around w/the camera: They were surrounded by 5 white columnar tornadoes, slowly churning in one place (or very slowly moving). It was ... weird, in an "otherworldly" way. Traffic kept flowing along and the folks w/ the camera didn't feel threatened (at that point).

Another tornado stand-out is video from the late 1950s, again in Texas. It was a super-creepy tornado, sooty gray-white, which had 4 little funnel clouds rotating around its attachment to the mother cloud. {{shivers}} Freaky. I've seen lots of tornado vids/pics, but that one takes the cake.


Thanks for the answers.

We have a storm chaser in our astronomy club. I keep telling him that all he has to do is park a mobile home in the middle of a corn field and then stand back and wait. The tornado should then find him.

Video may, after all, be considered a form of photography and subject to the same bias.

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Out at sea I know Tomcat pilots used to intentionally buzz through water spouts. If you hit them at the right speed you will exit at 45 degrees from your direction of travel.

When I first heard this I mentioned how "counter-intuitive" it sounded. I was told the any aircraft designed to go over mach 2 can do it and survive as a tornado spins at 300 knots max. Just don't do it over land or you could end up with a cow in your intake.

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