Geography

Concepts to cover

1. Cold weather season: western disturbances and winter rain in the north-west, north-east trades, temperature pattern
2. Hot weather season: loo, dust storms, kalbaisakhi, mango showers, cherry blossom showers
3. Onset over Kerala about 1 June and IMD criteria; advance of the two branches; whole country covered by about 8 July; duration decreases northward
4. Breaks in the monsoon: shift of the trough to the foothills, rain in the Himalaya and Tamil Nadu, dry plains
5. Retreating monsoon: withdrawal from September, October heat, north-east monsoon rain on the Coromandel coast, post-monsoon cyclones
6. Western disturbances as extra-tropical systems in the westerlies bringing winter rain and snow to north-west India