Air moves into a Low pressure system. It pushes any air that was there upwards.
Click on image for full size
Windows to the Universe original image
Clouds Formed by Air Being Forced to Rise
Some clouds form when air at the surface of the Earth is forced to rise. There are three processes that force air to rise.
First, in a low pressure system, wind moves in towards the center from all directions because air moves from high to low pressure. When this air meets in the center, there is nowhere for the air to go but up. Air is also forced to rise when it is traveling over land that slopes upward. The air cools as it rises, and eventually clouds will form. Finally, weather fronts produce clouds by causing air to rise when the lighter warm air flows over the heavier cold air.
All of the cloud types are formed by these processes, especially altocumulus, altostratus, cirrocumulus, stratocumulus, or stratus clouds.
Shop Windows to the Universe Science Store!Cool It!
is the new card game from the Union of Concerned Scientists that teaches kids about the choices we have when it comes to climate change—and how policy and technology decisions made today will matter. Cool It! is available in our online store
You might also be interested in:
Wind is moving air. Warm air rises, and cool air comes in to take its place. This movement creates different pressures in the atmosphere which creates the winds around the globe. Since the Earth spins,...more
Weather fronts can cause clouds to form. Fronts occur when two large masses of air collide at the Earth's surface. Warm fronts produce clouds when warm air replaces cold air by sliding above it. Many different...more
Altocumulus clouds (weather symbol - Ac), are made primarily of liquid water and have a thickness of 1 km. They are part of the Middle Cloud group (2000-7000m up). They are grayish-white with one part...more
Altostratus clouds (weather symbol - As) consist of water and some ice crystals. They belong to the Middle Cloud group (2000-7000m up). An altostratus cloud usually covers the whole sky and has a gray...more
Cirrocumulus clouds (weather symbol - Cc) are composed primarily of ice crystals and belong to the High Cloud group (5000-13000m). They are small rounded puffs that usually appear in long rows. Cirrocumulus...more
Stratocumulus (weather symbol - Sc) clouds consist of water droplets and belong to the Low Cloud (surface-2000m) group. These clouds are low, lumpy, and gray. These clouds can look like cells under a microscope...more
Stratus (weather symbol - St) clouds consist of water droplets and belong to the Low Cloud (surface-2000m up) group. They are uniform gray in color and can cover most or all of the sky. Stratus clouds...more