Storms 1 (lighting and thunderstorms)

5 types of lightning

Cloud ground

+ CG

-CG

Cloud Cloud

Intra-cloud

How much energy you need to make a spark in the air?

3 billion volts

Which occurs more? Intra cloud or Cloud Ground?

IC occurs 1-10 times more than Cloud Ground

Does lighting from the anvil travel a longer distance?

Yes, it can travel usually 12 km to the ground

What is characteristics of - CG strikes

way more numerous then + strikes

they come from cloud base

What is characteristics of + CG strikes

less frequent

they come from anvil

much stronger

cause wildfires

10-25% of canada CG lightning is +

How do you calculate how far the lighting is?

count number of seconds between when you SEE and HEAR and divide number of seconds —> kilometres

ex. 9 second difference = 3 km

What is the 30/30 rule?

if 30 seconds or less between you see flash and hear bang. move indoors and stay there for 30 minutes

What are safe places during lighting?

1) fully enclosed metal vehicle with windows up

2) substantial permanent building, dont use hard wire telephones

Areas to avoid during lightning

1) small structures, huts, rainshelters,

2) metallic objects

3) trees, water, open fields, hiltops

What is the lightning safety crouch?

feet together, hands over ears

What are characteristics of thunderstorms? (anatomy)

1) thick clouds w/ lighting and thunder

2) cloud near top of troposphere (anvil) 10-15 km

3) has cloud base (under 1km)

updrafts and downdrafts in thunderstorms

1) they have updrafts and downdrafts

2) if strong updraft —> dome overshoot above anvil

(looks like a hat)

3) main updraft (looks like mushroom stem)

how long can an anvil be?

100s of km in diameter

Where does storm energy come from?

temperature and humidity

what is CB?

CB stands for cumulonimbus which is just another word for thunderstorms

Thunderstorm cells evolution

they evolve during 15-30 minutes

multi-cell thunderstorms

they contain 2 or more cells, each cell is in different stages of evolution

squall line

a line of thunderstorms

supercell thunderstorm

a large rotating single cell storm.

-cause tornadoes, large hail, frequent lightning, heavy rain, strong winds

What are the 3 supercell types

1) low precipitation

2) classical

3) high precipitation

What are the 3 stages of the thunderstorm life cycle?

1) the cumulus stage

2) the mature stage

3) the dissipating stage

what is the cumulus stage?

updraft, no rain, no anvil

what is the mature stage?

up & down-drafts, heavy rain, crisp anvil

dissipating stage

downdraft, light rain, fuzzy anvil

What is the MAIN source of energy for thunderstorms?

the Sun!

What are the 3 different heights that solar energy is absorbed?

1) thermosphere

2) stratosphere

3) earth surface

the ground heats the air in the troposphere

What happens to the solar energy once it hits the ground?

some reflect back into clouds, some gets absorbed by ground making the ground warmer.

Whats the SENSIBLE heat aspect once solar energy warms ground?

sensible heat goes goes into air —> causes air to get warmer

Whats the LATENT heat aspect once solar energy warms ground?

latent heat into air (evaporates lakes) —> causes humidity to rise

What is the 2 fuels for storms

temperature and humidity

When is the greatest accumulation of heat ( what time of the day)?

during sunset

When does solar heating happen

during the day!

Infrared radiation (IR) cooling

day and night, its constant!

when is it most likely for a T storm to form?

late afternoon and early evening…why? because most accumulated heat!

Where are the most thunderstorms located

areas closer to equator but not on the equator (ex. florida, USA)

Advection

warm humid air carried by the wind