Thunderstorms

Question 1

The condition necessary for the formation of a thunderstorm are:

Answer 1

(a)Steep lapse rate, strong winds
(b)Shallow lapse rate, adequate supply of moisture
>(c) Steep lapse rate, adequate supply of moisture and trigger action

Question 2

Hail is most likely to fall from a cloud

Answer 2

(a)Having layers
(b)Composed of Ice crystals
>(c)Having strong vertical development

Question 3

Norwesters are

Answer 3

(a)The western disturbances which affect NW India
>(b)Severe thunderstorms which occur over NE India during hot weather period
(c)Severe thunderstorms which occur over Peninsula during hot weather period

Question 4

Duststorm usually occurs over NW India during

Answer 4

(a) Post-monsoon
(b) Winter
>(c) Pre-Monsoon

Question 5

A ‘mature’ thunderstorm has strong

Answer 5

(a) updraft only
(b) downdraft only
>(c) updrafts and downdrafts

Question 6

Aircraft icing is most favoured in the cloud which have temperatures ranging between

Answer 6

(a) -20°C and -40°C
>(b) 0°C and -20°C
(c) below -40°C

Question 7

A short duration, showery precipitation is associated with

Answer 7

(a) ST
(b) AS
>(c) CB

Question 8

Hail is

Answer 8

(a) Solid precipitation commonly occurring over the mountainous regions in winters.
(b) Frozen or partly frozen rain falling from sheet type of clouds
>(c) Solid precipitation falling from a deep convective cloud

Question 9

The most hazardous cloud for aviation is

Answer 9

> (a) CB
(b) CU
(c) NS

Question 10

The life of a Cb cell is usually

Answer 10

(a) 7 to 8 hrs
(b) 3 to 4 hrs
>(c) 2-3 hr

Question 11

Generally, the severest activity of a, heat type, TS is for

Answer 11

(a) 2 hrs
>(b) 30 to 45 min
(c) 3 to 4 hr

Question 12

Norwesters occur during

Answer 12

(a) Jan-Feb
>(b) Mar-May
(c) June-Sep
(d) Oct – Dec

Question 13

Norwesters occur during

Answer 13

(a) Winter
>(b) Hot weather
(c) Monsoon
(d) Post Monsoon

Question 14

Norwesters affect

Answer 14

(a) N India
>(b) Bengal, Bihar, Orissa and Assam
(c) Central India

Question 15

The trigger action may take place due to

Answer 15

(a) Clear night sky, no wind
>(b) Orographic lifting
(c) high pressure

Question 16

Norwesters normally occur during

Answer 16

(a) Mornings
>(b) Afternoons
(c) Nights

Question 17

Norwesters originates over
(a) Chota-Nagpur hills
(b) Deccan Plato
(c) Khasi hills

Answer 17

> (a) Chota-Nagpur hills
(b) Deccan Plato
(c) Khasi hills

Question 18

Andhi (blinding storms) occur generally over

Answer 18

(a) S India
>(b) N India
(c) NE India

Question 19

Wind speed in Light DS is

Answer 19

(a) 25 kt
(b) 30 kt
>(c) up to 21 kt

Question 20

The diameter of Microburst is

Answer 20

> (a) less than 4 km
(b) less than 2 km
(c) less than 6 km

Question 21

The diameter of and Macroburst

Answer 21

(a) > 4 km
>(b) 4 km or more
(c) > 8 km

Question 22

For detecting precipitation a Radar wavelength in the range ………….. is suitable

Answer 22

> (a) 30 to 200 mm
(b) 400-500 mm
(c) 600-700 mm

Question 23

For airborne radars wavelength generally used

Answer 23

(a) 20 mm
(b) 40 mm
>(c) 60 mm

Question 24

The wavelength of TS detection X band radar is

Answer 24

(a) 10 mm
(b) 20 mm
>(c) 30 mm

Question 25

The wavelength of storm detection S band radar is

Answer 25

(a) 50 mm >(b) 100 mm (c) 200 mm

Question 26

Over plains TS mostly occur during the

Answer 26

>(a) afternoon (b) night (c) early morning

Question 27

Over valley and foot hills TS generally occur during

Answer 27

(a) afternoon >(b) night & early morning

Question 28

Over the sea TS are more frequent

Answer 28

a) afternoon >(b) night (c) early morning

Question 29

The life of Mesoscale Convective Complex TS is

Answer 29

(a) 2-3 hr (b) 3-4 hr >(c) 6 to 24 hr

Question 30

Loud peals of thunder, frequent flashes of lightning, moderate or heavy showers accompanied y light hail with maximum wind speed 15-40 kt is classified as

Answer 30

(a) Light TS >(b) Moderate TS (c) Severe

Question 31

For a severe TS one of the requirements is strong Wind Shear

Answer 31

(a) Horizontal >(b) Vertical (c) Slant

Question 32

Severe TS cells arc tilted

Answer 32

>(a) in vertical (b) to the South (c) to the North

Question 33

When flying through on active TS, lighting strikes are most likely

Answer 33

(a) Above 5000 ft and under the anvil. (b) In the clear air below the cloud in rain >(c) In the temperature band between +10° and -1O°C (d) At or about 10000 ft

Question 34

Hazards of the mature stage of a TS Cell include lighting, turbulence and:

Answer 34

(a) Microburst, wind-shear and anvil >(b) Icing, microburst and WS (c) Icing, drizzle and microburst (d) WS, hail and fog

Question 35

Hail grows by

Answer 35

(a) freezing as it leaves the cloud (b) up and down forces in CU cloud (c)Collision with Ice crystals >(d) collision with supercooled water drops