You see, hail, rainfall, snow, dew, (and even mist and fog) is formed in huge cumulonimbus clouds, commonly known as thunderheads. When the ground is heated during the day by the sun, the air close to the ground is heated as well. Then, hot air, being less dense and therefore lighter than cold air, rises and cools. As it cools, its capacity for holding moisture decreases. When the rising, warm air has cooled so much that it cannot retain all of its moisture, water vapor condenses, forming puffy-looking clouds. The condensing moisture releases heat of its own into the surrounding air, causing the air to rise faster and give up even more moisture.
Cumulonimbus clouds contain vast amounts of energy in the form of updrafts and downdrafts. These vertical winds can reach speeds over 176 kilometers (110 miles) per hour. The water, (whatever it happens to form into depending on the temperature: hail, snow, rain, etc...) grows in the storm cloud's main updraft, where most of the cloud is in the form of "super-cooled" water. This is water that remains liquid although its temperature is at or below zero degrees Celsius (32 degrees Fahrenheit). At temperatures higher than -40 degrees C (-40 degrees F), super-cooled water drop needs something on which to freeze, or it remains liquid. Ice crystals, frozen raindrops, dust and salt from the ocean are also present in the cloud. On collision, super-cooled water will freeze onto any of these hosts, creating new hailstones in this example, or enlarging those that already exist.
2006-08-10
03:37:00
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13 answers
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asked by
Cool Akshay
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Social Science
➔ Gender Studies