chuong 13

the condition necessary for the formation of a thunderstorm are

• steep lapse rate, strong winds

• shallow lapse rate, adequate supply of moisture

• steep lapse rate, adequate supply of moisture and trigger action

hail is most likely to fall from a cloud

• having layers

• composed of ice crystals

• having strong vertical development

norwesters are

• the western disturbances which affect NW india

• severe thunderstorms which occur over NE India during hot weather period

• severe thunderstorms which occur over Peninsula during hot weather period

duststorm usually occurs over NW India during

• post-monsoon

• winter

• pre-monsoon

a "mature" thunderstorms has strong

• updraft only

• downdraft only

• updraft & downdraft

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

• -20 do C and -40 do C

• 0 do C and -20 do C

• below -40 do C

a short duration, showery precipitation is associated with

• ST

• AS

• CB

Hail is

• solid precipitation commonly occurring over the mountainous regions in winters

• frozen or partly frozen rain falling from sheet type of clouds

• solid precipitation falling from a deep convective cloud

The most hazadous cloud for aviation is

• CB

• CU

• NS

The life of a Cb cell is usually

• 7 to 8 hrs

• 3 to 4 hrs

• 2 to 3 hrs