With dozens of people killed in just 3 days, heavy rainfall and consequent flooding has ravaged India's northern region.
This downpour has been caused by an "interaction" between a western disturbance and the southwest monsoon, as per the Indian Meteorological Department.
There was "good" monsoon circulation over India, and simultaneously, a western disturbance passed over the region.
Two types of winds - strong westerly and moist easterly from Bay of Bengal - converged over northwest India, and led to the severe weather condition.