Clouds DO move.
Contrary to what some people believe, clouds do move. Some people theorize that the movement of the clouds is actually an optical illusion caused by the rotation of the earth. Although clouds are in the atmosphere and might seem detached from planet Earth, the atmosphere is still a part of the Earth and rotates along with the solid portion of the planet. Another theory is that clouds do not actually move; they simply dissolve and re-form continuously along their leading edge. However, clouds do move both vertically and horizontally.
Wind Moves Clouds
Clouds are a collection of water vapor that is not visible but always moving. Clouds form when water vapor mixes with condensation nuclei, such as dust, pollen, and smoke. This forms a visible cloud mass when reflected by sunlight. Atmospheric wind will push this cloud mass even when it isn’t windy near the Earth’s surface, it may be occurring at higher elevations.
Clouds Move Vertically
The very formation of clouds is triggered by a rising air mass that climbs in altitude into colder air. This temperature change causes the moisture in the cloud to condense into droplets. As a cloud continues to rise, it will continue to grow until it is saturated with water droplets and begins to rain or until it is acted upon by winds. As a cloud loses moisture it tends to sink into warmer air closer to the earth, and the moisture in the cloud eventually evaporates to the point that the cloud disappears completely.
Clouds Move Horizontally
The horizontal movement of clouds can be steered by upper level winds, including the jet stream. Cirrus clouds generally indicate the direction of upper level winds. Clouds also move horizontally when acted upon by cold fronts and warm fronts. Both types of fronts are characterized by the movement of air. In a cold front, cold air moves into an area to replace warm air. In a warm front, warm air moves into an area to replace cold air. In either case, the air movement between the two air masses can generate winds that move the clouds forward in the direction of the wind. In addition to horizontal movement, vertical movement of clouds can also occur with cold and warm fronts as warm air rises over colder air.
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