Thunderstorms Flashcards
The condition necessary for the formation of a thunderstorm are:
(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
Hail is most likely to fall from a cloud
(a)Having layers
(b)Composed of Ice crystals
>(c)Having strong vertical development
Norwesters are
(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
Duststorm usually occurs over NW India during
(a) Post-monsoon
(b) Winter
>(c) Pre-Monsoon
A ‘mature’ thunderstorm has strong
(a) updraft only
(b) downdraft only
>(c) updrafts and downdrafts
Aircraft icing is most favoured in the cloud which have temperatures ranging between
(a) -20°C and -40°C
>(b) 0°C and -20°C
(c) below -40°C
A short duration, showery precipitation is associated with
(a) ST
(b) AS
>(c) CB
Hail is
(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
The most hazardous cloud for aviation is
> (a) CB
(b) CU
(c) NS
The life of a Cb cell is usually
(a) 7 to 8 hrs
(b) 3 to 4 hrs
>(c) 2-3 hr
Generally, the severest activity of a, heat type, TS is for
(a) 2 hrs
>(b) 30 to 45 min
(c) 3 to 4 hr
Norwesters occur during
(a) Jan-Feb
>(b) Mar-May
(c) June-Sep
(d) Oct – Dec
Norwesters occur during
(a) Winter
>(b) Hot weather
(c) Monsoon
(d) Post Monsoon
Norwesters affect
(a) N India
>(b) Bengal, Bihar, Orissa and Assam
(c) Central India
The trigger action may take place due to
(a) Clear night sky, no wind
>(b) Orographic lifting
(c) high pressure
Norwesters normally occur during
(a) Mornings
>(b) Afternoons
(c) Nights
Norwesters originates over
(a) Chota-Nagpur hills
(b) Deccan Plato
(c) Khasi hills
> (a) Chota-Nagpur hills
(b) Deccan Plato
(c) Khasi hills
Andhi (blinding storms) occur generally over
(a) S India
>(b) N India
(c) NE India
Wind speed in Light DS is
(a) 25 kt
(b) 30 kt
>(c) up to 21 kt
The diameter of Microburst is
> (a) less than 4 km
(b) less than 2 km
(c) less than 6 km
The diameter of and Macroburst
(a) > 4 km
>(b) 4 km or more
(c) > 8 km
For detecting precipitation a Radar wavelength in the range ………….. is suitable
> (a) 30 to 200 mm
(b) 400-500 mm
(c) 600-700 mm
For airborne radars wavelength generally used
(a) 20 mm
(b) 40 mm
>(c) 60 mm
The wavelength of TS detection X band radar is
(a) 10 mm
(b) 20 mm
>(c) 30 mm
The wavelength of storm detection S band radar is
(a) 50 mm
>(b) 100 mm
(c) 200 mm
Over plains TS mostly occur during the
> (a) afternoon
(b) night
(c) early morning
Over valley and foot hills TS generally occur during
(a) afternoon
>(b) night & early morning
Over the sea TS are more frequent
a) afternoon
>(b) night
(c) early morning
The life of Mesoscale Convective Complex TS is
(a) 2-3 hr
(b) 3-4 hr
>(c) 6 to 24 hr
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
(a) Light TS
>(b) Moderate TS
(c) Severe
For a severe TS one of the requirements is strong Wind Shear
(a) Horizontal
>(b) Vertical
(c) Slant
Severe TS cells arc tilted
> (a) in vertical
(b) to the South
(c) to the North
When flying through on active TS, lighting strikes are
most likely
(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
Hazards of the mature stage of a TS Cell include lighting, turbulence and:
(a) Microburst, wind-shear and anvil
>(b) Icing, microburst and WS
(c) Icing, drizzle and microburst
(d) WS, hail and fog
Hail grows by
(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
