The inflow of western disturbances moves under the influence of westerly jet streams from the Mediterranean Sea.
It influences winter weather conditions over most parts of Northern Plains and Western Himalayan region.
It brings little rain in winter months.
This rain is considered to be very good for wheat crops in northern plains.
The tropical cyclones also develop in the Bay of Bengal.
The frequency and direction of these cyclones influence weather conditions along the eastern coast during October, November and December.