twisters came in clockwise or anti clock wise direction?or both why do twisters occur?

Answer 1

twisters come in counterclockwise in the northern hemisphere and clockwise in the southern hemisphere.

A tornado is a violently rotating column of air which is in contact with both a cumulonimbus (or, in rare cases, cumulus) cloud base and the surface of the earth. Tornadoes can come in many shapes, but are typically in the form of a visible condensation funnel, with the narrow end touching the earth. Often, a cloud of debris encircles the lower portion of the funnel.

Tornadoes often develop from a class of thunderstorms known as supercells. Supercells contain mesocyclones, in which rotation is organized. Most intense tornadoes (F3 to F5 on the Fujita Scale) develop from supercells. Very heavy rain, frequent lightning, strong wind gusts, and hail are also common in such storms. The largest hail generally comes from supercells, as a very strong and rotating updraft is usually required to suspend such large hailstones aloft

Answer 2

the direction of a twister is not a result of the northern versus southern hemisphere. The Coriolis effect which imparts a minor directional flow based on the rotation of the earth is not capable of providing enough influence on the direction of rotation to control the direction of spin. If your really bored poll all your neighbors about the directions their sinks drain, you might be surprised.

Now for tornadoes, Tornadoes from when hot air rises and cold air descends along a weather front called a super cell. The resulting motion causes rotation which forms into a tornado. Researchers have made great strides in unrecognizing the weather patterns that are most likely to form a tornado, but since the mechanics of a tornado's aren't completely understood nobody can forecast them with certainty.