meteorology review: precipitation formation

would have been lecture 5 module 4

0.02 mm, 2 mm

Cloud droplets are __________ in diameter, while a typical raindrop is __________ in diameter.

1 million

The volume of a typical raindrop is __________ times that of a cloud droplet.

incredibly slowly

Due to their small size, cloud droplets fall through still air __________.

several hours

An average cloud droplet falling from 1,000 meters would require __________ to reach the ground.

1 million

For precipitation to form, cloud droplets must grow in volume by __________ times.

Bergeron process, collision-coalescence process

The two processes responsible for precipitation formation are the __________ and the __________.

cold, 0°C (32°F)

The Bergeron process operates in __________ clouds at temperatures below __________.

supercooled

__________ water can exist in a liquid state at temperatures below 0°C.

freezing

In the atmosphere, supercooled droplets freeze on contact with __________ nuclei.

-15°C (5°F)

Freezing nuclei become effective at temperatures of __________ or colder.

supersaturated

When air surrounding a water droplet is saturated, it is __________ relative to a nearby ice crystal.

ice crystals, snow crystals

In the Bergeron process, water vapor deposits on __________ to form __________.

snowflakes

The Bergeron process produces a chain reaction that forms __________ in cold clouds.

warm, -15°C (5°F)

The collision-coalescence process occurs in __________ clouds with tops warmer than __________.

coalesce

Collision-Coalescence Process

In this process, cloud droplets collide and __________ to form larger raindrops.

terminal velocity

Collision-Coalescence Process

Larger droplets fall faster due to their higher __________ relative to their surface area.

around a million

Collision-Coalescence Process

To grow to the size of a raindrop, cloud droplets need to coalesce __________ times.

hamburger bun

Collision-Coalescence Process

As raindrops grow, their shape changes, with large drops resembling a __________ shape.

break apart

Collision-Coalescence Process

When raindrops grow too large, they __________ into smaller drops.

raindrops

Collision-Coalescence Process

This process is responsible for forming __________ in warm clouds.

snow, lower

In thunderstorms, the Bergeron process generates __________ that melts on descent and coalesces in the __________ region of the cloud.

rain, snow, sleet, freezing rain

The four main types of precipitation are __________, __________, __________, and __________.

snow, bergeron

All precipitation starts as __________ in cold clouds, due to the __________ process.

deep warm

Rain occurs when snow falls into a __________ layer above freezing, causing it to completely melt.

freezing, unaffected

Snow occurs when the entire atmospheric layer is at or below __________, allowing it to fall __________.

thin, deep

Sleet occurs when snow melts in a __________ layer above freezing air and refreezes in a __________ layer of below-freezing air.

thick, thin

Freezing rain occurs when snow encounters a __________ layer of above-freezing air and then a __________ below-freezing layer, causing it to freeze on contact with the ground.