<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (May 2016) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (May 2016) (Learn how and when to remove this template message) </Td> </Tr> <P> A Western Disturbance is an extratropical storm originating in the Mediterranean region that brings sudden winter rain to the northwestern parts of the Indian subcontinent . It is a non-monsoonal precipitation pattern driven by the westerlies . The moisture in these storms usually originates over the Mediterranean Sea and the Atlantic Ocean . Extratropical storms are a global phenomena with moisture usually carried in the upper atmosphere, unlike their tropical counterparts where the moisture is carried in the lower atmosphere . In the case of the Indian subcontinent, moisture is sometimes shed as rain when the storm system encounters the Himalayas . </P> <P> Western Disturbances are important for the development of the Rabi crop, which includes the locally important staple wheat . </P>

Account for the winter rain in northern india