What creates the strong wind in a thunderstorm???

Question

What creates the strong wind in a thunderstorm???

Answer 1

Damaging wind from thunderstorms is much more common than damage from tornadoes. In fact, many confuse damage produced by "straight-line" winds and often erroneously attribute it to tornadoes. Wind speeds can reach up to 100 mph (161 kph) with a damage path extending many miles.

Downdrafts are generated when rain-cooled, more dense air sinks inside a thunderstorm. Also some of the strong winds aloft are carried down with the downdraft by a process called "momentum transfer". As precipitation begins to fall, it drags some of the air with it. This "precipitation drag" initiates a downdraft. The downdraft is intensified by evaporative cooling as drier air from the edges of the storm mix with the moist air within the storm.

Downbursts are divided into two categories; macrobursts and microbursts. A macroburst is more than 2½ miles (4 km) in diameter and can produce winds as high as 135 mph (215 kph). Microbursts are smaller and produces winds as high as 170 mph (270 kph).

In wet, humid environments, macrobursts and microbursts will be accompanied by intense rainfall at the ground. If the storm forms in a relatively dry environment, however, the rain may evaporate before it reaches the ground and these downbursts will be without precipitation, known as dry microbursts.

These processes lead to a rapid downward rush of air. As the air impacts the ground it is forced to spread out laterally causing the gusty winds associated with thunderstorms. Occasionally, thunderstorms will produce intense downdrafts that create damage as the wind spread out along the ground.

http://www.srh.noaa.gov/jetstream/tstorm...

Answer 2

Cold air versus hot or warm air.

Answer 3

The downdraft from the cumulonimbus cloud which reaches the surface and spreads in all directions with great force causes the strong winds.The details follow.

There are three important stages in the formation and dissipation of the cumulonimbus cloud which produces thunderstorm.They are developing stage,mature stage and dissipating stage.

In the developing stage,the core of the cloud is warmer and hence only a general updraft is experienced .As the cloud develops,the hydrometeors(ice,water, snow etc) are no longer supported by the updraft and the mature stage begins.In the mature stage,the frictional drag due to the hydrometeors retards the updrafts .Melting of snow and ice below freezing level cools the air inside the cloud.The downdraft with strong cold  air along with hydrometeors increase in extent and the updraft is weakened and vanishes ultimately.In the dissipating stage,the downdraft spreads hirizontally within the cloud  and occupies major portion of the cloud.There is no appreciable source of water vapour to condence and the cloud starts dissipating with a strong downdraft of  cold air which hits the surface and spreads in all direction with great force resulting in strong winds.This persists for sometime and ultimately the cloud completely dissipates.