How do clouds form, and what makes them rain?
470292
When sun shines on water, it warms it up and since heat is lighter, the water kinda floats up into the air. That's called evaporating. Then when it's high in the sky, many little water droplets come together and from clouds. When there's too many water droplets, the cloud becomes to watery and it rains. Then it starts all over again.
936340
Mushroom clouds form as a result of the sudden formation of a large mass of hot low-density gases near the ground creating a Rayleigh-Taylor instability. The mass of gas rises rapidly, resulting in turbulent vortices curling downward around its edges and drawing up a column of additional smoke and debris in the center to form its "stem". The mass of gas eventually reaches an altitude where it is no longer less dense than the surrounding air and disperses, the debris drawn upward from the ground scattering and drifting back down (see fallout).\nhello, use the link below to get more info.
1166276
Clouds are mists of water droplets that have condensed out of water vapour at "dewpoint", which is dependent on temperature, pressure, and humidity.\n\nThere is no intelligence or knowing involved.\n\nClouds don't fly, they are blown by the wind.
173251
A cumulonimbus cloud forms in rising air (updraft).  The air cools as it rises, and at a certain point the water vapor in the air condenses into water droplets, forming a cloud.  Around a large Cb there is often downdraft - the air gets warmer as it subsides, and any water droplets (=clouds) will evaporate.
33298
3 things r neede for cloud formation...cooling of air, presence of water vapour (relative humidity shud be close to 100%), and condensation nuclei( like dust particles).\ndunno who found it, sorry
818482
A cloud is a visible mass of condensed droplets or frozen crystals suspended in the atmosphere above the surface of the Earth or another planetary body. The branch of meteorology in which clouds are studied is nephology.\n\nOn Earth, the condensing substance is water vapor, which forms small droplets of water or ice crystals, typically 0.01 mm in diameter. When surrounded with billions of other droplets or crystals, they are visible as clouds. Dense deep clouds exhibit a high reflectance (70% to 95%) throughout the visible range of wavelengths: they thus appear white, at least from the top. Cloud droplets tend to scatter light very efficiently, so that the intensity of the solar radiation decreases with depth into the cloud, hence the grey or even sometimes dark appearance of the clouds at their base. Thin clouds may appear to have acquired the color of their environment or background, and clouds illuminated by non-white light, such as during sunrise or sunset, may be colored accordingly. In the near-infrared range, however, clouds would appear very dark because the water that constitutes the cloud droplets strongly absorbs solar radiation at these wavelengths.\n\nCloud formation and properties\nClouds form when the invisible water vapor in the air condenses into visible water droplets or ice crystals. This can happen in three ways:\n\n1. The air is cooled below its saturation point. This happens when the air comes in contact with a cold surface or a surface that is cooling by radiation, or the air is cooled by adiabatic expansion (rising). This can happen:\n* along warm and cold fronts (frontal lift)\n* where air flows up the side of a mountain and cools as it rises higher into the atmosphere (orographic lift)\n* by the convection caused by the warming of a surface by insolation (diurnal heating)\n* when warm air blows over a colder surface such as a cool body of water.\n\n2. Clouds can be formed when two air masses below saturation point mix. Examples are breath on a cold day, aircraft contrails and Arctic sea smoke.\n\n3. The air stays the same temperature but absorbs more water vapor into it until it reaches saturation point.\n\nThe water in a typical cloud can have a mass of up to several million tonnes. However, the volume of a cloud is correspondingly high, and the net density of the relatively warm air holding the droplets is low enough that air currents below and within the cloud are capable of keeping it suspended. As well, conditions inside a cloud are not static: water droplets are constantly forming and re-evaporating. A typical cloud droplet has a radius on the order of 1 x 10-5 m and a terminal velocity of about 1-2 cm/s. This gives these droplets plenty of time to re-evaporate as they fall into the warmer air beneath the cloud.\nCumulonimbus cloud\nEnlarge\nCumulonimbus cloud\n\nMost water droplets are formed when water vapor condenses around a condensation nucleus, a tiny particle of smoke, dust, ash, or salt. In supersaturated conditions, water droplets may act as condensation nuclei.\n\nWater droplets large enough to fall to the ground are produced in two ways. The most important means is through the Bergeron Process, theorized by Tor Bergeron, in which supercooled water droplets and ice crystals in a cloud interact to produce the rapid growth of ice crystals; these crystals precipitate from the cloud and melt as they fall. This process typically takes place in clouds with tops cooler than -15°C. The second most important process is the collision and wake capture process, occurring in clouds with warmer tops, in which the collision of rising and falling water droplets produces larger and larger droplets, which are eventually heavy enough to overcome air currents in the cloud and the updraft beneath it and fall as rain. As a droplet falls through the smaller droplets which surround it, it produces a "wake" which draws some of the smaller droplets into collisions, perpetuating the process. This meth
415254
It rains when the air can no longer hold onto the moisture in an evaporated, cloud form.  It can be cold and rainy, mild and rainy, or hot, muggy and rainy.  \n\nMoisture moves on the air currents. During winter, rain usually comes when it is cold because the air currents bring COLD air from the far north (remember the "jet stream" they talk about on the news?)  But when air currents from the tropics move overhead, temperatures are warmer because it isn't cold in the tropics. And tropical air often brings a huge amount of rain (think hurricanes).\n\nDuring summer, if there is moisture in the air, a lot of moisture, it condenses and turns into liquid form (rain) when temperatures and moisture content of the clouds reaches the right combination.
272453
Cirrus clouds form at high altitudes and usually don't create precipitation. Also, any other form of high-level cloud, such as altocumulus, altostratus, etc. usually don't produce precipitation that reaches the ground.
972997
Hail forms when water frezes as it falls and then wind blows it back up high befor it hits the ground.  It colects another layer of water that frezes, and if the wind is strong enough, it will fly back up, and the cycle repeats untill the wind is not strong enough to cary the hevy ball of frozen water back up.\nSnow forms when water droplets in clouds freeze and crisylise.
799074
How scientific do you want it?\n\nBasically, air circulates the earth.\n\nThis air has different temperatures in different places.\n\nThe different temperatures cause different pressures of air masses.\n\nBecause of this air flows around air masses due to the pressure gradient between different masses.\n\nThis air flow drags air of even higher temperature differences into contact.\n\nDifferent air temperatures meet causing one to rise over the other, as this rising air goes up it cools and causes clouds (These areas where air masses join are the fronts on a weather map).\n\nThese clouds then produce rain.\n\nThat rain changes temperatures, more air masses are drawn into contact, and the cycle repeats.
492491
Water vapor is transparent (for most purposes) and so mere humidity in the atmosphere can't be a cloud. Since clouds don't have motors keeping them in the air, and yet stay there for hours in some cases, they can't be solid, for if they were, they'd fall out of the sky and we'd find cloud bits laying around on the ground. And the same is true for liquid as well. \n\nSo what's a cloud? Mostly, it's very small bits, so small that air currents can keep them in the air. The bits can be solid (eg, ice crystals of which snowflakes are examples), or liquid (eg, little drops of water, of which rain is an example). In either case, enough of these small things begin to look white as light passes thorough them and is reflected and refracted and generally diverted. Kind of like the effect of fine particulate suspensions in water. They are sometimes referred to as milky looking. Indeed, milk is white for a similar reason.\n\nThese are usually formed around dust bits, for real. High humidity (forced by cooling temperatures) produces supercooling (ie, ready to condense, if a trigger can be found). The dust motes provides the trigger. With updraft winds, a condensed drop can grow pretty large. And if it goes high enough, and gets cold enough, the drop can freeze (and thus make hail). If the orignal condensation is sufficiently cold, then water will be added to an ice crystal. With the proper history, such crystals become snowflakes.
1116902
The mechanism of Cloud formation is still not understood. Researchers are now applying Chaos Theory in the study and modelling of cloud behavior.\n\nWe "see" clouds only when the high moisture regions are sufficiently close to refract and reflect light. Actually they are highly dynamic systems.
1156612
Water vapour is a colourless, transparent gas - so clouds are quite clearly not made of it.\n\nClouds are indeed made of small drops of water. They stay up becaus of convection. Clouds can only be stable where there is an updraft to counter the slow drift down of the water droplets under gravity. \n\nThere are two basic types - stratiform which are stable and supported by a constant updraft and convective in which you can actually see the churning effect of convection if you look.
5861
No.  The cloud will form when the ambient temperature inside the cloud is lower than the dew point.  The moisture may actually form snow (on a summer day!) which melts on the way down to form rain.  The temperature outside the cloud may be less relevant because clouds often form when a column of moisture-laden air rises locally condensing into a  cloud right above the column.
1030331
The clouds form when air near the earth's surface is warmed, causing it to rise since warm air rises. Think of a marshmallow in a microwave; as the microwave heats the marshmallow it begins to expand. This is similar to most things, like air. When air heats up it expands and this expanding air has to go somewhere because it is taking up more space, just as the marshmallow does, so this expanding warm air rises. Well, as the air rises it is losing its heat and cooling. When things cool, they condense; think of the marshmallow again as it cools when you take it out of the microwave (it shrinks, or condenses). In a general sense, to give you a brief idea of how clouds form, when condensation occurs, clouds take shape; you must keep in mind, however, that there is much more involved in cloud formation, but this was just to get you thinking and give a place for the lightning to happen.\n\nThe tendency of charges within a cloud is to have positive charges gather toward the upper portion and negative charges in the bottom of the cloud. \nWhen the difference between these charges is great enough to overcome the air's natural insulation, which keeps these charges from mixing, a lightning flash can take place. This charge difference builds up to millions of volts before the stoke of lightning takes place. The lightning bolt actually happens because nature tries to maintain equilibrium, a state of balance between all things. This is why the lightning that you see is a discharge of energy in the form of electricity. \n\nyea..thats the scientific answer to why it strikes...hope u can undertand it....i got it in skool\n\nas for how far away it is\n\ni learned that it comes from the "eye" of the storm or the center, && after the lightning flashes, count mississippi & the number of seconds equals a rought amount of miles you are away from the "eye" of the storm\n\nhope that helps
756259
Clouds are made of miniscule water droplets.  When you consider how enormous clouds are (in volume), all those water droplets can add up to a very high weight.  Think how heavy a glass of water is.  Now let's try to extrapolate how much vapor that will make -- perhaps 5-10 cubic feet?  Now multiply that number of glasses by how many cubic feet of space a cloud takes up...\n\n<quote>\n\n"The water in a typical cloud can have a mass of up to several million tonnes. However, the volume of a cloud is correspondingly high, and the net density of the relatively warm air holding the droplets is low enough that air currents below and within the cloud are capable of keeping it suspended. As well, conditions inside a cloud are not static: water droplets are constantly forming and re-evaporating. A typical cloud droplet has a radius on the order of 1 x 10-5 m and a terminal velocity of about 1-2 cm/s. This gives these droplets plenty of time to re-evaporate as they fall into the warmer air beneath the cloud."\n\n</quote>
346255
I can't remember exactly but its something like this.  Large, tall clouds form.  Vapour freezes (hail). Updraught occurs which is strong enough to support the weight of the hailstones inside the cloud.  Hailstones move and collide  getting bigger until updraught can't support the weight anymore and they fall, air temperature is cool enough to keep stones frozen until they reach the ground.