A Tornado At Sea would be Called a waterspout.
There are two types of waterspout.
Tornadic waterspouts form the same way as normal tornadoes do, only the form on or move onto water. For information on this, see the ling to the related question below.
The second and more common type of waterspouts are fair weather waterspouts which are typically weaker than ordinary tornadoes.
They typically form from developing thunderstorms over relatively water mater. They start when the water is warmer than the air above it and warms the layer just above the surface. This warm, moist air will tend to rise, and, if there is surface-level vorticity in the area may start to rotate. As this spinning updraft matures it can connect to the updraft the feeds a developing storm above it and further intensify to from a waterspout.
Tornadoes can happen in any place that gets thunderstorms.
Tornadoes happen in Miami for the same reason they happen anywhere else. See the related question for how tornadoes form in general.
Tornadoes can happen in Ottawa. Canada does get tornadoes, though not as often as the U.S. due to its cooler climate.
Tornadoes can happen anywhere in the world except cold areas like Antarctica and the north pole. Tornadoes are mostly common in United States.
Yes. Tornadoes, including some significant ones, can and do happen the the Philippines.
Tornadoes happen in the summer every year.
Most tornadoes in the U.S. happen in spring and early summer.
Tornadoes can happen anywhere - they're usually formed from severe thunderstorms.
Sicily Tornadoes happened in 1851.
well tornadoes can happen anywhere any time so yes
Tornadoes happen in all seasons but are most common in the spring.
Tornadoes do not happen IN the Gulf of Mexico. Tropical storms and hurricanes happen in the Gulf of Mex, but not tornadoes. Tornado-like features over water are called waterspouts.