Storms 2

Question 1

what is a remote sensor?

Answer 1

an instrument from outside of the storm that can measure the storm

Question 2

What are some REMOTE sensors that measure storms?

Answer 2

Radar
Satellite

Question 3

What do radars see?

Answer 3

rain inside storm
up and downdraft stem of mushroom cloud

Question 4

Using radars, the Disaster Intensity Scale for… indicates …

Answer 4

Radar-Echo Strength (dBZ)
- indicate rainfall rate

Question 5

What are squall lines?

Answer 5

a line of many thunderstorms
- forms along a cold front
- hail, lots of lightning, possibly tornadoes

Question 6

Three types of supercells

Answer 6

1. Low precipitation
   - lots of hail
2. Classic
   - rainy downdraft, rain free updraft
3. high precipitation
   - updraft surrounded by rain

Question 7

what are mixed mode or hybrid storms?

Answer 7

Contains features of 2 or more types of supercells

Question 8

Downpours can cause

Answer 8

flash floods
- dBZ scale is extreme

Question 9

can arc clouds occur at the anvil?

Answer 9

no!

Question 10

describe thunderstorm diagram

Answer 10

Thunderstorm
|
V arc cloud + warm air
precipitation downburst gust front + haboob

Question 11

downdraft speeds

Answer 11

20-90 km/h

Question 12

horizontal wind speeds near ground

Answer 12

up to 250km/h

i.e. outburst

Question 13

Microbursts

Answer 13

small diameter downbursts
~ 1km

Question 14

What are downbursts?

Answer 14

cold & dense air sinking

Question 15

Why do downbursts occur?

Answer 15

Tstorm can create dense air where rain falls
- due to evaporative cooling

Question 16

Hazards of downbursts

Answer 16

often invisible but a hazard to aircraft

Question 17

What are Gust Fronts?

Answer 17

leading edge of cold, horizontal, straight-line winds

Question 18

Why do gust fronts occur?

Answer 18

downburst air hits ground & spreads outward in straight lines, in all directions

Question 19

What can gust fronts look like?

Answer 19

1. haboob = if dry ground
2. arc cloud = if moist air
3. gustnado

Question 20

Safety measures

Answer 20

avoid weak buildings & trees that can fall

Question 21

Arc clouds are along…

Answer 21

gust fronts

Question 22

What are haboobs

Answer 22

sand storms that occur at edge of gustfronts

Question 23

What is the fuel for storms?

Answer 23

moist air

Question 24

Storms can ____ (4 things)

Answer 24

1. draw in humid air
2. cause air to condense
3. release heat into the storm
4. result in precipitation & violent winds

Question 25

Humidity

Answer 25

amount of water vapour in the air

Question 26

What is the mixing ratio (humidity)

Answer 26

amount of water vapour ÷ amount of all OTHER gases (not including water)

Question 27

Saturation

Answer 27

the maximum humidity that air can hold - Equilibrium between Evaporation and Condensation (i.e. the rate matches)

Question 28

What is important in controlling atmospheric humidity?

Answer 28

saturation value

Question 29

How does Saturation Mixing Ratio increase with Temperature?

Answer 29

increases exponentially

Question 30

What air can hold more water vapour at equilibrium, warm or cold?

Answer 30

warmer air!

Question 31

When it is not cloudy, what does this mean in terms of air and water vapour?

Answer 31

unsaturated air is holding less water vapour

Question 32

when it is cloudy or foggy, what does this mean in terms of air and water vapour?

Answer 32

air contains max amount of water vapour (i.e. is saturated)

Question 33

Advection

Answer 33

movement of air by the wind ex/ water vapour can be advected into a Tstorm by the wind

Question 34

Adiabatic cooling

Answer 34

removing heat by evaporating water when a thermal of unsaturated air rises adiabatically (with no heat transfer to the environment), the thermal cools roughly 10C/km of rise

Question 35

What process releases latent heat?

Answer 35

condensation

Question 36

Why does condensation occur?

Answer 36

cooler air can hold less water vapour, so they condense into droplets i.e. oversaturated! When the saturation humidity value < actual humidity

Question 37

What does condensation do? (3 things)

Answer 37

1. release latent heat into sensible heat -> make storms warmer 2. reduce humidity down to equilibrium (saturation) value 3. increase liquid cloud drops, can grow to be rain drops

Question 38

What is a mesocyclone

Answer 38

A rotating thunderstorm

Question 39

What is the typical humidity value?

Answer 39

1/ (78+21) ~ 1/99

Question 40

Most thunderstorms contain how many cells?

Answer 40

2 or more Multicell thunderstorms