What makes a cloud percipitate?

Question

A thunderstorm recently passed by my house, and I was wondering, what makes a cloud all of the sudden break out raining? I was watching a newscast and the weather report made it look like after all of the clouds had passed onto land, they all began raining simultaniously. Is it a critical density? Does this happen once over land? Is it something completely different?

Thanks.

Answer 1

The simple answer is that the air is rising and condensing.  Fog does not cause rain because there isn't any verticle movement in fog.

Answer 2

All clouds do not produce rain.Under certain conditions,millions of very tiny water droplets  combine together within the cloud to form bigger rain drops which fall as rain due to weight.

In the case of thunder clouds,if the updraft is no longer able to lift the rain drops or the hail stones,they fall as rain or hail.

Answer 3

When water evaporates it gets into the atmosphere. When when the moisture in the air reaches the dew point and condenses, it becomes a cloud or fog.

Rain clouds form when the heat from the ground causes an updraft which causes the moisture below the cloud to move upwards into the cloud and condense. When the drops get so large the updraft cannot keep them aloft the fall to the ground as rain. Sometimes under favorable atmospheric condition, this can take place over a large area.

When moisture ladened air from the sea comes to shore over hot land, the updraft takes the moisture ladened air very high where it condenses and falls to earth. This can occur as a daily pattern under some conditions.

Answer 4

-warm air can hold more moisture then cold air.

-when warm air rises it cools about 3-4*F every 1000 ft

- the warm air will continue to cool with altitude untill the air molecules cant hold more moisture

-the dewpoint or 100% saturation is reached and its rains

-if you know the ground temp.and the dew point temp. you can figure out approximately how high the clouds are...

-ex...80* F grnd temp  -  60* dew point  =  20*

-air will cool 3-4*F about every 1000ft so 20*/ 4*= 5 or 5000ft

-clouds are at 5000 ft alt.

-earth/soil can heat up and cool down quickly and to extremes

while water maintains a more consistant temperature range.   -the variations in these surface temps influence air above them which usually causes wacky weather on the shorline or around lakes and so on. Hope that helped alittle.

Answer 5

Clouds composed entirely of liquid must contain some droplets larger than 20 micrometers if precipitation is to form. Such large droplets form when "giant" condensation nuclei are present. The giant drops fall most abundantly and collide with the smaller, slower droplets. Growing larger in the process, they fall even more rapidly, increasing their chances of collision and rate of growth. After a great many such collisions they are large enough to fall to the surface without completely evaporating. This is known as the "Collision and Coalescence Process" We just recently learned this in class and I have my final exam tomorrow!

For thunderstorms there is the whole developmental sequence of cumulonimbus clouds: first it goes through the cumulous stage. Then there is the Mature stage, and lastly the Dissipating stage. You can research this one online if you want to go further in depth with it. There is a lot to explain about the Mature Stage.