Clouds and Precipitation

Adiabatic Temp. Change and Expansion and cooling

• Unsaturated air• Wet adiabatic rat is always lower than dry • Temp. changes happen even if heat isn’t

added or subtracted.

Orographic Lifting

• Occurs when elevated terrains act bas barriers to the air flow.

• Air goes up a mountain slope, is compresses and cooling often generates clouds.

• Many rainiest places have windward slopes.

Frontal Wedging

• Masses of warm air and cold air collide• Denser air acts, less dense air rises • Middle-latitude are used for storm systems

Convergence

• Air masses forces air to rise• The lower it is, it starts to lift• Warm days the air is from the ocean to the

land

Localized Convective Lifting

• Warm days, unequal heating of Earths surface may cause some pockets of air to be warmed

• Warming of air is called thermal • Process the products rising thermals is

localizes convection lifting.

Stability

• Air is forced to rise• Temperature would drop because of expansion• Volume of air was cooler than the surrounding

environment.

Condensation

• Happens when water vapor in the air changes to a liquid

• For condensation to occur, the air must be saturated

• Saturated occurs at dew point or when water vapor is added in the air

Types of clouds

• Cirrus- clouds are high, white, occur ad patches

• Cumulus- consist if rounded individual cloud mass, have flat bases

• Stratus- are like sheets, or a layer that covers most the of sky

High Clouds

• All high clouds are thin & white. • Temperature is low with small quantities of

water vapor presents a high altitude• Clouds are not considered precipitation

markers

Middle clouds

• Range to 2000 to 6000 meters • Have prefix of alto • White to grayish color of sheet

Low Clouds

• Stratus, Stratocumulus, and Nimbostratus• cloud growth is a type in common when air id

forced upwards• Stable air can result in a cloud layer that is

largely horicaontal

Clouds Of Vertical Development

• Clouds don’t fit into any of the three height categories.

• Have bases in low height range but extended upward

• Once upward movement is triggered, acceleration is powerful, clouds with great vertical rang form.

Fog

• No difference between fog and a cloud• Defined as a cloud • When fog is dense, visibility may be few dozen

meters for less

Cold Clouds Precipitation

• Relies on two physical processes: super cooling and supersaturating

• Cloud droplets to not freeze at 0c • Rainfall can deal with clouds located below

the freeing point

Warm Clouds Precipitation

• Mechanism forms raindrops, in the collision-coalscence process

• Salt can remove water vapor form the air• Large droplets move through clouds, collide

and coalesce

Rain and Snow • Rain mean drops of water falling from clouds• Snow melt and continue their descent as rain

before they reach the ground• Light, fluffy snow made up of individual six-

sides ice crystals

Sleet, Glaze and hail

• Sleet is the fall of small particles of clear to translucent ice

• Glaze is known for freezing rain, raindrops become super-cooled

• Hail is produced in cumulonimbus clouds, hailstones begin as small ice pellets that grow by collection super-cooled water droplets