Prelims 23457

Which among the following is/are the characteristic features of the weather associated with Lee Depressions?
1. Low velocity winds
2. Dark nimbus clouds
3. Showery rainfall
Which of the statements given above is/are correct?
A.
1 and 2 only
B.
1, 2 and 3
C.
2 and 3 only
D.
1 and 3 only
Explanation :
These weather disturbances are produced on the lee side of the mountain barriers. When the Westerlies are blocked by the north-south mountain barrier, the air flow undergoes contraction over the ridge and expansion on the lee side. Thus, there is a convergence and cyclonic curvature in the lee of the barrier. Such depressions are common in winter to the south of the Alps and the Atlas Mountains and also in Texas and Colorado areas. These depressions develop all the characteristics of an extra-tropical depression. Dark nimbus clouds, Showery rainfall or snowfall and high velocity winds are some of the characteristic features of the weather associated with these depressions. Hence only statements 2 and 3 are correct.