why when its very cold ,the clouds dont freeze and just fall down as a block of ice :s?
85299
When it is very cold clouds do freeze. In fact even on a hot summer’s day the high clouds are normally frozen. \n\nThe reason they don’t; fall down is because ice isn’t any heavier than liquid water. When you freeze the droplets that make up a cloud they don’t gain any weight, they just turn from a liquid to a solid. You can prove this your self by  filling an ice cube tray with water and weighing it. After you freeze it solid you can weigh it again and the weight will be EXACTLY THE SAME.\n\nBecause frozen clouds made of ice are no heavier than clouds made of liquid water there is no reason why they should fall down. \n\nClouds are made of billions of tiny droplets of water. You can see this for yourself if you go outside on a foggy night with a flashlight. Fog is nothing but a cloud that has formed very close to the ground, and the flashlight beam will show that the fog cloud is made up of lots of little drops of water floating in the breeze. \n\nA cloud is kept in the sky because the wind is constantly blowing those tinny water drops upwards and preventing them from falling. When those droplets freeze they are still blown around in the wind like tiny little snowflakes (but they are not snowflakes).
196823
The fact that ice always floats on water should give you a clue!  The ice is obviously not as dense.  So you can infer from this something has happened during the freezing process.\n\nThe structure of a water molecule is One atom of hydrogen to two if oxygen.  As the water freezes hydrogen bonds form between the various water molecules and these stop the molecules packing as effectively so the ice is less dense.\n\nTry the source below.
191055
clouds fall all the time, in the form of rain or snow. The cloud is not a container for moisture, it IS the moisture.  \n\nLuckily, it falls gently or heavily, but not all at once!  I think maybe you were asking "what if a cloud fell all at once," in which case I'd say YIKES.  Kind of like a tsunami from the sky, I guess!
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.
284203
Ice lowers the melting point of water, so it causes the ice to turn to liquid water and break up.  If it's *really* cold, this doesn't help.
1180769
No.\n\nSleet is frozen droplets of water (usually used to mean soft snow like pellets in Europe and hard ice pellets in the US). These typically bounce when they hit the ground.\n\nFreezing rain is supercooled droplets of liquid water. These freeze on contact with the ground (or anything else indeed). For this reason, freezing rain can be far more treacherous because it leads to very slippery conditions, and if it forms ice on structures such as power cables or trees the weight can cause them to fail.
1098665
Many people think that snow is just frozen rain that falls to the ground. The true process occurs in the clouds, when ice crystals form from the water vapor. This process is called sublimation and describes the solid form of snow forming directly from the vapor phase of water, without passing through the liquid water phase (rain).\n\nIt turns out that "pure" snow is made up of snowflakes, which are made up of 2 to 200 separate snow crystals. Snow crystals are crystals that have formed around tiny bits of dirt that have been carried up into the atmosphere by the wind. \n\nThe type of crystals depends on the amount of humidity and temperature present when they are forming. When cloud temperature is at freezing or below and the clouds are moisture filled, snow crystals form. The ice crystals form on dust particles as the water vapor condenses and partially melted crystals cling together to form snowflakes. As the snow crystals grow, they become heavier and fall towards Earth.\n\nAs the snowflakes move throughout the cloud, it crystallizes in different ways producing unpredictable shapes and sizes. When it’s very cold and snowing, the flakes are small, and when it’s closer to 32 degrees Fahrenheit, the flakes are larger.
79449
Clouds are composed of small water droplets and/or ice crystals, depending on temperature. It's H2O in some form. Lower clouds are generally water droplets, while high clouds such as cirrus clouds are made up of ice crystals.
615371
If the air cools to truly frigid Arctic temperatures such as -40 C and below then the moisture capacity of the air will be so low that likely not much snow can occur. Only at these extremely low temperatures is the phrase "it is too cold to snow" fairly valid.\n\nAt the temperature of absolute zero ( 0 K, -273 C, -459 F) all air including water vapor condenses and loses all molecular energy. The temperature can not cool below absolute zero. \n\nIts can't snow in deep space.......
308423
It all depends upon the layers of temparature in the atmosphere.  If an upper layer where the precipitation originates is below freezing then it can snow even if it is above freezing at ground level.  Reverse those temperatures and you get freezing rain.
150463
There are a couple of reasons that work together to explain this situation. The first one has to do with how raindrops form. \n\nNow, it may seem silly to make such an obvious statement as, "Rain always falls from clouds." But once it has been said, we can then ask, "What is going on inside those clouds?" And that question leads us to plenty of relevant information! \n\nDo you remember the last time your local weather was described as being "hot and humid"? Do you remember what it FELT like? Do you also remember what the air LOOKED like? The reason I am asking these questions is because it is important to know that ordinary water is commonly found in one of three forms: solid, liquid, or gas. The liquid form is what we call "water", while the solid form we call "ice", and the gas form we call "water vapor". Water vapor is colorless, odorless, and invisible. But you sure can FEEL it on a hot and humid day! \n\nNext, do you remember the last time you encountered some fog? Think about what IT looked like. If you looked real close, you would have seen zillions of tiny tiny droplets of water floating in the air. And, if you remember the last time you saw some steam, you might think that it looked just like fog (except it was hotter). Steam is NOT pure water vapor! \n\nWell, it happens that the description, "zillions of tiny tiny droplets of water floating in the air", applies to every fog, to every mist, to every burst of steam -- and to every cloud in the sky. If you sit back and simply watch the clouds for a while, you will see that some clouds grow, some shrink, and some do nothing but move across the sky. What is happening to the growing or shrinking clouds? When a cloud grows, water vapor in the air gradually "condenses" to form lots more tiny tiny droplets. When a cloud shrinks, many droplets are completely "evaporating" to become invisible water vapor. \n\nAs the winds move air across the sky, carrying clouds along, fragments of wind known as "eddys" can do strange things to the shapes of clouds. A common game is to study a cloud's shape and guess what it looks like. Also, winds from different directions can collide with each other, which often has great effects upon clouds. It depends on how cold or warm the colliding winds are, and how much water each wind carries (only the differences matter, not whether the water is in the form of vapor or tiny drops). \n\nFor rain to happen, the weather conditions inside the clouds, and surrounding them, has to cause the droplets to grow. Some droplets will grow by colliding and combining with each other -- just what you Asked about. Some droplets will grow by acquiring more and more water vapor from the air. Some will do both. But the important thing to remember now is that MOST of the droplets in the clouds grow at the same time! \n\nBUT, the droplets do not all grow at the same rate; some grow faster than others. As soon as ANY get big enough, they start to fall out of the cloud. Water is heavier than air, after all. Depending on the wind conditions, those first raindrops might be blown back up into the cloud, where they can grow some more. Eventually, however, they get too big to stay up in the air, so they fall all the way to the ground. And the slower-growing droplets will fall after them, and the slower-growing-yet droplets will fall after THEM, and so on. This is the essence of the raining process. \n\nAs I said at the start, there are a couple of reasons why the raindrops don't combine to make a single stream. The first reason is simply that raindrops start falling just as soon as they are too heavy to stay in the air. The second reason is that they are all falling together DOWNWARDS, not sideways. If the wind blows them sideways, they all move TOGETHER sideways. That isn't good enough to cause them to meet each other, while falling, so they could combine to form a si
307036
The clouds hang in the air due to buoyancy (density of water vapour is less than air). At higher altitudes the air becomes thinner and force of buoyancy is lesser. so they cant hang at higher altitudes.
614817
Wrong.  \nFrozen rain is called frozen rain (clever,eh?).\n\nHail is formed when rain is swept upward in a thunderstorm to a freezing altitude, falls and is swept up again repeatedly until the size of the hailstone is too much for the upgoing air to support.  Enough cycles of this can result in some killer size stones.........
601596
Clouds 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\nalong warm and cold fronts (frontal lift), \nwhere air flows up the side of a mountain and cools as it rises higher into the atmosphere (orographic lift), \nby the convection caused by the warming of a surface by insolation (diurnal heating), \nwhen warm air blows over a colder surface such as a cool body of water. \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.\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 water vapor is actually low enough that air currents below and within the cloud are capable of keeping small droplets 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 give these droplets plenty of time to re-evaporate as they fall into in the warmer air beneath the 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 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, which 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, thus perpetuating the process. This method of raindrop production is the primary mechanism in low stratiform clouds and small cumulus clouds in trade winds and tropical regions, and produces raindrops of several millimeters diameter.\n\n \nThis wave cloud pattern formed off of the Île Amsterdam in the far southern Indian Ocean.The actual form of cloud created depends on the strength of the uplift and on air stability. In unstable conditions convection dominates, creating vertically developed clouds. Stable air produces horizontally homogeneous clouds. Frontal uplift creates various cloud forms depending on the composition of the front (ana-type or kata-type warm or cold front). Orographic uplift also creates variable cloud forms depending on air stability, although cap cloud and wave clouds are specific to orographic clouds.
390105
What are clouds?\nA cloud is a large collection of very tiny droplets of water or ice crystals. The droplets are so small and light that they can float in the air. \n\nHow are clouds formed?\nAll air contains water, but near the ground it is usually in the form of an invisible gas called water vapor. When warm air rises, it expands and cools. Cool air can't hold as much water vapor as warm air, so some of the vapor condenses onto tiny pieces of dust that are floating in the air and forms a tiny droplet around each dust particle. When billions of these droplets come together they become a visible cloud. \n\nWhy are clouds white?\nClouds are white because they reflect the light of the sun. Light is made up of colors of the rainbow and when you add them all together you get white. The sun appears a yellow color because it sends out more yellow light than any other color. Clouds reflect all the colors the exact same amount so they look white.\n\nWhy do clouds turn gray?\nClouds are made up of tiny water droplets or ice crystals, usually a mixture of both. The water and ice scatter all light, making clouds appear white. If the clouds get thick enough or high enough all the light above does not make it through, hence the gray or dark look. Also, if there are lots of other clouds around, their shadow can add to the gray or multicolored gray appearance.\n \nWhy do clouds float?\nA cloud forms when air heated by the sun. As it rises, it slowly cools it reaches the saturation point and water condenses, forming a cloud. As long as the cloud and the air that its made of is warmer than the outside air around it, it floats!\n\nHow do clouds move?\nClouds move with the wind. High cirrus clouds are pushed along by the jet stream, sometimes traveling at more than 100 miles-per-hour. When clouds are part of a thunderstorm they usually travel at 30 to 40
726978
The warm air pushes the moisture higher into the colder air layers....as the moisture droplets freeze together  they fall and enter the warm air currents which pushes them back up to the cold layers..this happens until enough layers are built up, that the updrafts can't support the weight and the ice falls to the ground in the form of hailstones.
4143
Before it begins to snow, the system begins to cool the air down to ground level.  As this happens, moisture in the ground moves up into the weather system, and eventually mixes with the already cold water, ect within the cloud.  As the snow begins to fall, the temprature drops for a short period of time, and then stabilizes. \n\nThis stabilization happens so that the snow can continue to fall without turning into ice.  On average, winter snow will fall between 14 F and 30 F.  However, it is possible for snow to fall at lower tempratures, however you will see an increase in temprature to have snow fall.\n\nNot all snow falls, however, fall within that temprature range.  Area's such as alaska, greenland, siberia, ect, can have snow even when it is much much colder.  However, the general rule still applies:  snow fall equels an increase in temprature untill a stabilization point has been reached.\n\nSnow that falls within the normal range is usualy wet snow, ie it is snow that is mixed with a bit of melted snow (water vapor), thus causing it to be heavy snow.\n\nSnow that falls below the temprature range tends to be dry snow, ie, snow that has completely frozen over.\n\nDry snow can be a major problem as it doesn't allow for the stabilization to occure at a quick rate, instead, blizzards, huge snow storms, ect, can take effect before the storm system actually stabilizes.\n\nHope that made sens&#92;e