Question

What do you understand by a break in monsoon?

Answer 1

Hint:
Break monsoon conditions do not last for more than 3 days. However, sometimes this could last for more than a fortnight. Longer break monsoon conditions are referred to as 'spoilsport' for Indian monsoon for which the concluding result could be drought or failure of monsoon.


Complete solution:
Monsoon refers to a seasonal reversal in the wind direction during a year. Monsoon, at times, possesses 'breaks' in rainfall, indicating that there are wet and dry spells left in between. The monsoon rains take place irregularly and gradually starts to take place in the rainless intervals.

When tropical disturbances increase along the monsoon trough, then at times the sea level's low-pressure area has the chances to weaken and resulting in the conversion of the low-pressure area from 900 mb to 700 mb height in order to move at the north side of the trough.

After the high level low-pressure area shifts towards the north, precipitation comes to a decrease in the side of northern plains. North Bay of Bengal is replaced with a high-pressure area due to the low-pressure area.

This makes the monsoon trough along the west coast to weaken and monsoon winds from Bay of Bengal branch mainly feed the monsoon trough that runs along the foothill of the Himalayas and Northeast India.

This concludes less or no rainfall across the west coast, Deccan plateau and Northern plains. But also a low-pressure trough forms over the Tamil Nadu coast which in turn enhances the rainfall. As the monsoon trough runs close to foothills of Himalayas, monsoon winds ascend the slopes of the Himalayas resulting in orthographic rainfall. This is how a monsoon break works.

Note:
These breaks in the different regions are due to different reasons:
1) In northern India rains are likely to fail if the rain-bearing storms are not very frequent
along the monsoon trough or the ITCZ over this region.
2) Over the west coast the dry spells are associated with days when winds blow parallel to
the coast.