decode the secrets of the sky
Predict the weather and find your way home when you understand the clouds and stars.
DAY: CLOUD COMPUTING
Most of us know to run for cover from dark, ominous cumulonimbus clouds. But some tufts are stealthier. Cirrus, like cotton candy wisps streaming high in the sky, are typically fair-weather friends. But if they’re moving, they can signify a front arriving within 24 hours. Cirrostratus, resembling a filmy veil, can predict precipitation within 12 to 24 hours.
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cirrus - thin, wispy, usually white
- seen in fair to pleasant weather
- predict a weather change within 24 hours
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cirrocumulus - rows of small white puffs
- usually indicate fair, cold weather
- can predict a hurricane in tropical climates
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cirrostratus - thin, sheetlike
- often cover the entire sky
- predict rain or snow
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altostratus - gray or blue-gray
- made of ice crystals and water droplets
- often predict continuous rain or snow storms
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altocumulus - gray puffy masses
- usually form in groups
- if seen in the morning, predict thunderstorms in the afternoon
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stratus - uniform fog-like gray clouds
- sometimes produce light mist or drizzle
- if seen in the morning, they usually burn off
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stratocumulus - low, puffy and gray
- form in rows with blue sky in between
- may predict slight chance of light rain
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nimbostratus - dark gray, wet-looking layer
- associated with continuous rain or snow
- often predict light to moderate precipitation
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cumulus - white, puffy clouds
- often called fair-weather clouds
- can turn into giant cumulonimbus clouds/thunderstorm clouds
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cumulonimbus - high winds flatten them into anvil-like shape
- anvil often points in direction storm is moving
- predict with heavy rain, snow, hail, lightning, even tornadoes
Old School Tools
Before meteorology, farmers and fishermen devised mnemonic proverbs to help them respond to the sky's signals. Challenge your family to a game of fact or fiction on these gems:
“Red sky at night, sailor’s delight. Red sky in the morning, sailor’s warning.” This adage holds some water. A red sunset generally signifies that high pressure, associated with calm weather, is keeping dust near the earth’s surface. Red in the morning, however, could mean a high pressure front has already passed over from west to east. Low pressure might be nipping at its heels, boding inclement weather. Batten down the hatches, skipper!
“Lightning never strikes twice.” Actually, it does, particularly when tempted by sky-high structures. New York City’s Empire State Building is struck by a bolt about 23 times every year.