Western disturbances only impact Western Himalayas between October and February. Although Western disturbances travel throughout the year but during summer months they tend to travel in upper altitudes.
Winter rain and snowfall over Western Himalayas usually occur due to the impact of Western Disturbance. Punjab, Haryana, Delhi, Uttar Pradesh and north Rajasthan also witness rainfall during the winter months.
Now, the first active Western Disturbance is expected to approach Western Himalayas by the night of October 18th. There are chances of snowfall over the upper reaches of Jammu and Kashmir, Himachal Pradesh, Ladakh and Uttarakhand on October 19 and 20. The lower district of these states may experience scattered rain during this period.
The intensity of rain and snow will not be very heavy. Minimum temperatures are expected to increase marginally however, day temperatures may drop by 2 to 3 degrees Celsius. Now the intensity and frequency of Western disturbances will increase gradually the peak intensity is expected during month of December and January.