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Survival Techniques – How to read clouds

Knowing how to read clouds can be important to survival. Clouds foretell the weather and give
you warning about what you should do next and how you should prepare. Some of the weather
conditions that they can predict are snow, ice, rain, thunderstorms, tornadoes and fog. Clouds
are classified according to their height and their appearance from the ground. ________________________________________________________________________________________
                                                  The following cloud roots:
                                                     Cirro-high, curl of hair
                                                    Nimbo- rain, precipitation

High-level clouds:

High-level clouds occur above about 20,000 feet. The clouds are composed of ice crystals and appear thin, streak and white.


       High-level Clouds
The three main types of high clouds are cirrus, cirrostratus, and cirrocumulus. Cirrus clouds are wispy,
feathery, and composed
entirely of ice crystals. They often are the first sign of an approaching warm front or upper-level jet streak.


Cirrostratus clouds form more of a widespread, veil-like layer. 

       Cirrostratus Clouds
As a warm front approaches,
cirrus clouds tend to thicken into cirrostratus, which may, in turn, thicken and lower
into altostratus, stratus, and even nimbostratus.


Cirrocumulus clouds are layered clouds with small cumuliform lumps. They also often line up in rows of clouds across the sky.


       Cirrocumulus Clouds



Mid-level clouds:

These clouds appear 6,500 to 20,000 feet in the sky and depending on the altitude, time of year, and vertical temperature structure of the troposphere, these clouds may be composed of liquid water droplets, ice crystals, or a combination of the two. The two main types of mid-level clouds are altostratus and altocumulus.


       Mid-Level Clouds


These clouds frequently indicate the approach of a warm front and may thicken and lower into stratus and predict rain or snow.


Low-level clouds:

Low clouds occur below 6500 feet, and normally consist of liquid water droplet. During cold winter storms, ice crystals and snow comprise much of the clouds.



       Low-Level Clouds

The two main types of low clouds include stratus, which develop horizontally, and cumulus, which develop vertically. Stratus clouds are uniform and flat, producing a gray layer of cloud cover which may be precipitation-free or may cause periods of light precipitation or drizzle. On cold, dismal, gray weather can linger for several hours or even a day or two.


Stratocumulus clouds are hybrids of layered stratus and cellular cumulus, individual cloud elements, characteristic of cumulo type clouds, clumped together in a continuous distribution, characteristic of strato type clouds.

      Stratocumulus clouds

These clouds appear frequently in the atmosphere, either ahead of or behind a frontal system.


Nimbostratus clouds are dense stratus or stratocumulus clouds.

      Nimbostratus clouds


Produces steady rain or snow.

Cumulus clouds are cellular, have flat bottoms and rounded tops and grow vertically. A cumulus cloud that exhibits significant vertical development but is not yet a thunderstorm is called cumulus congestus or towering cumulus.


      Cumulus Clouds


If enough atmospheric instability, moisture, and lift are present, then strong updrafts can develop in the cumulus cloud leading to a mature, deep cumulonimbus cloud that means a thunderstorm can produce heavy rain.


In addition, cloud electrification occurs within cumulonimbus clouds due to many collisions between charged water droplet, ice-water mix, and ice crystal particles, resulting in lightning and thunder.



A Wall Cloud is localized cloud lowering from the rain-free base of a strong thunderstorm. The lowering denotes a storm's updraft where rapidly rising air causes lower pressure just below the main updraft, which enhances condensation and cloud formation just under the primary cloud base.


      A Wall Cloud

Wall clouds take on many shapes and sizes. Some exhibit strong upward motion and cyclonic rotation, leading to tornado formation, while others do not rotate and essentially are harmless.


Shelf Cloud: A low, horizontal, sometimes wedge-shaped cloud associated with the leading edge of a thunderstorm’s outflow or gust front and potentially strong winds.


      Shelf Cloud


Although often appearing ominous, shelf clouds normally do not produce tornadoes.


Fractus: Low, ragged stratiform or cumuliform cloud elements that normally are unattached to larger thunderstorm or cold frontal cloud bases.




Fractus clouds are also known as scud, can look ominous, but by themselves are not dangerous.


Mammatus: Drooping underside of a cumulonimbus cloud in its latter stage of development.



Mammatus most often are seen hanging from the anvil of a severe thunderstorm, but do not produce severe weather. They can accompany non-severe storms as well.


Contrail: Narrow, elongated cloud formed as jet aircraft exhaust condenses in cold air at high altitudes.


These clouds are indicative of upper level humidity and wind drift.




Fog: These clouds are layers of stratus clouds that are near the ground. Different types include radiation fog that forms overnight and burns off in the morning and advection fog.