Thunderstorms

Question 1

what is the Thunderstorm (TS) cloud

Answer 1

Cumulonimbus (CB)

Question 2

What does a TS need to form ?

Answer 2

Unstable atmosphere
High Humidity (lots of water vapour)
Initial lifting action

Question 3

CB cloud specs

Answer 3

• Great vertical extent
• Upper cld spreads out into smooth anvil of cirrus cld

Ragged patches
Rolling motion

Question 4

CB Composition

Answer 4

• Water droplets
• Supercooled water drops
• Snowflakes
• Hail
• Ice crystals

Question 5

CB weather associated

Answer 5

• +SHRA
• Snow (SN)
• Hail (GR)
• Lightening
• Squalls (SQ)
• Tornadoes
• Water spouts
• Turbulence

Question 6

What is the developing stage of a TS

Answer 6

Towering Cumulus TCU

Question 7

What is a well developed TS cloud

Answer 7

• Extreme vertical development
• Cirrus cap spreads out not anvil shape

Question 8

How does it form ?

What are the Stages ?

Answer 8

Needed -> large Cumulus CLD with Vigorous growth

Growing Stage
- Air movement upwards within cloud
- Updrafts suspending large water droplets & snow
- Virga sometimes present

Mature Stage
- Updrafts = Support water drops in cloud to grow
- Water drops become to big
- Downdrafts = friction between falling drops & air
- Strong vertical wind sheer -> from up & down drafts
- Then -> lightning, wind shear, violent squalls, heavy rain & hail

Dying Stage
- Updrafts stop
- Icy cap of cirrus pulled downwind into anvil
- CLD now cooler then environment
- Downdrafts weaken
- Edges of CLD are ragged
- CLD begins to evaporate