Withdrawal of SW Monsoon
- a) Withdrawal from extreme north-western parts of the country is not attempted before 1st September.
- b) After 1st September:
The following major synoptic features are considered for the first withdrawal from the western parts of NW India.
- i) Cessation of rainfall activity over the area for continuous 5 days.
- ii) Establishment of anticyclone in the lower troposphere (850 hPa and below)
- iii) Considerable reduction in moisture content as inferred from satellite water vapour imageries and tephigrams.
Further Withdrawal from the Country
- i) Further withdrawal from the country is declared, keeping the spatial continuity, reduction in moisture as seen in the water vapour imageries and prevalence of dry weather for 5 days.
- ii) SW monsoon is from the southern peninsula and hence from the entire country only after 1st October, when the circulation pattern indicates a change over from the southwesterly wind regime.