The formation of ordinary tornadoes is complicated.
First, a condition called wind shear, in which the speed or direction of the wind changes with altitude. If the shear is strong enough it can essentially tilt a thunderstorm, this separates the updraft and downdraft of the thunderstorm, preventing them from interfering with one another. This allows the storm to become stronger and last longer.
Additionally, if the wind shear is strong enough it can start the air rolling in what is called horizontal vorticity. This horizontal vorticity can then be turned vertical by a thunderstorm's updraft. When this happens, the thunderstorm may start rotating. The rotation is especially strong in an updraft called a mesocyclone. If the storm intensifies rapidly enough, a relatively warm downdraft called a rear-flank downdraft or RFD can wrap around the bottom part of the mesocyclone. This can then tighten and intensify its rotation and bring it down to the ground to produce a tornado.
There are two types of waterspout. First there are tornadic or type 1 waterspouts. These are ordinary tornadoes that happen to be on water, and form by the mechanism detailed above.
More common atre type 2 or fair weather waterspouts. These are weaker than regular tornadoes and can form from an ordinary thunderstorm, or even a towering cumulus cloud. Both thunderstorms and cumulus cloud generate an updraft. If they occur over a relatively warm body of water the updraft at the surface can be strengthened. If there is any hint of rotation in the air, which can occur on its own, it can get caught up in the updraft, tightened, and intensified to produce a waterspout. This mode of formation is more like that of dust devils than it is of tornadoes.
Tornadoes usually form on land, but they can form on water in which case they are called waterspouts.
Some tornadoes form as waterspouts and then move on to land, but not usually.
Tornadoes or twisters usually form over land. But sometimes they form over water as waterspouts.
Tornadoes usually form on land, but they can form on water too. In that case they are called waterspouts.
Not usually. Most tornadoes form over land. Occasionally they form over water and are called waterspouts.
Sometimes. Most waterspouts form by a different mechanism than typical tornadoes do, but sometimes an ordinary tornado occurs on water and so is considered a waterspout.
Tornadic and fair weather waterspouts. Tornadic waterspouts are ordinary tornadoes that form from the mesocyclone of a supercell and just happen to be on water. Fair weather waterspouts are generally weaker than tornadic waterspouts. They form from developing storms that occur over water that is warmer than the air above. They form in a manner more like that of dust devils than ordinary tornadoes. Most waterspouts are of the fair weather variety.
Tornadoes usually form on land, though they can form on water, win which case they are called waterspouts.
No. Ordinary tornadoes are usually more dangerous. Most waterspouts form by a different mechanism from tornadoes. They are weaker and rarely come on land, and dissipate quickly if they do.
Tornadoes are generally more dangerous as they are stronger than waterspouts.
To start off, we must establish that there are two types of waterspout: fair-weather waterspouts and tornadic waterspouts. Tornadic waterspouts are ordinary tornadoes that just happen to develop or move out over water. Fair-weather waterspouts are a different phenomenon. This answer will address the differences between tornadoes and fair-weather waterspouts.Similarities:Both tornadoes and waterspouts are small-scale vortices in which air-spirals upward.Both are usually short-lived.Both produce strong winds.Both have low pressure at their centers, which often leads to the formation of a condensation funnel.Both are associated with cumulonimbus or cumulus clouds.A waterspout that strikes land and causes damage is counted as a tornado.Differences Tornadoes are generally stronger than waterspouts. Winds in waterspouts often range from 40 to 60 mph and usually do not exceed 70 mph. Winds in tornadoes may commonly range from 70 to 110 mph, with rare cases exceeding 300 mph.Tornadoes form from a larger-scale circulation called a mesocyclone within an intense thunderstorm. Waterspouts form from small-scale convection under a thunderstorm or even a cumulus cloud.Tornadoes can persist on both land and water relatively unhindered while waterspouts usually dissipate quickly if they hit land.Tornadoes are, on average, larger than waterspouts.Several waterspouts can sometimes occur at the same time within a small area. This is rare for tornadoes.Tornadoes sometimes exhibit a multiple vortex structure, which is not seen in waterspouts.
Not usually. Most waterspouts are weaker than ordinary tornadoes and often dissipate when they hit land. However, some waterspouts, called tornadic waterspouts, are simply ordinary tornadoes that form or move onto water.
No. Waterspouts are spinning columns of air, similar to tornadoes. They form as a result of conditions just above the water's surface, rather than in the water itself.
No. Waterspouts are generally smaller than most tornadoes. Though a few are in the same size range that tornadoes typically fall into.
Not usually. There are two types of waterspout: "fair weather" waterspouts and "tornadic" waterspouts. Fair weather waterspouts are the more common variety. These are produced the the instability that results from cool air moving over warm water. They are usually much weaker than true tornadoes. Tornadic waterpouts are normal tornadoes that just happen to be on water.
Sort of. "Waterspouts" that form on land are called landspouts or simply tornadoes.
Yes. Tornadoes formed over water are called waterspouts.
No, water tornadoes, properly called waterspouts, usually form over water that is warmer than the air above it.
Tornadoes on water are called waterspouts.
"Water tornadoes," which are called waterspouts, are divided into two categories. Fair-weather waterspouts, are structured differently and generally weaker than classic tornadoes. Tornadic waterspouts are ordinary tornadoes that happen to be on water, they are just as strong as ordinary tornadoes.
Water tornadoes, properly called waterspouts, form best when the water temperature is higher than the air temperature.
Not really. Waterspouts require a much larger body of water to form, such as a lake. However, there are land based cousins of waterspouts called landspouts. In structure they are more like waterspouts than normal tornadoes. It is possible for one to strike a swimming pool, but it would be purely coincidental.
They are called waterspouts. They are usually much weaker than tornadoes though, as most form by a different mechanism than their land-based cousins.
Most waterspouts form by a different mechanism than the typical tornado. Tornadoes are most often a product of powerful rotating thunderstorms called supercells, the strongest thunderstorms on earth. Most waterspouts don't form from supercells, but are a result of the instability that occurs when cool air moves over warm water, which doesn't provide as much power.