Western disturbances are extratropical, mid-latitude synoptic-scale weather systems (embedded as troughs within the westerly Rossby wave pattern) that originate over the Mediterranean/Caspian/Atlantic region and travel eastward, approaching the Indian subcontinent from the west, bringing winter precipitation (including snowfall) to Jammu and Kashmir and adjoining northwestern India; they are fundamentally a mid-latitude westerly (Rossby wave) phenomenon and are not related to equatorial Kelvin wave dynamics, which instead govern tropical, equatorially-trapped disturbances such as those associated with the Madden-Julian Oscillation or ENSO.