14 / 20
When a cold front crosses a mountain range, its activity..
  • A
    ceases immediately.
  • B
    strengthens "upwind" of the mountains.
  • C
    is not disturbed by the mountains.
  • D
    decreases when it reaches the mountains.

Refer to figure.

"Activity" refers to cloud formations (such as cumulonimbus/thunderstorms) => typical weather associated with cold fronts.

Sometimes a cold front will approach the mountain range and then much of the cold air will initially be held back by the range. When this unstable air finally breaks over the mountains and is forced to ascend - lifting will occur with additional lifting from the orographic low.
Orographic lifting in unstable air, alone, can produce cumulus or cumulonimbus clouds and also thunderstorms if there is enough water vapour present. In mountainous areas, this may be very active and produce extensive cloud and vertical development.

Therefore, we can say that the orographic lifting experienced upon hitting the mountain, will supplement the already existing convective lifting, intensifying the convective activity (CBs and TS) => The result can be heavy banks of Cb, with line squalls, very heavy showers, thunderstorms, hail and poor visibility.

The upwind side of the mountain, for instance, is the first side the approaching force hits.

Your Notes (not visible to others)



This question has appeared on the real examination, you can find the related countries below.