Likely developments for the advance of Southwest Monsoon 2022
Apart from the rainfall which can be influenced by many factors such as pull effect winds due to a cyclone, we look at some other wind patterns of the Monsoon which is a characteristic of the Monsoonal regime.
Following are some salient features of wind patterns of the Monsoon:
1) Westerlies at lower tropospheric levels (till ~600 hPa)
2) Easterlies in the upper atmospheric levels (~200 hPa)
3) Cross equatorial winds should turn to form the Somali Jet for the Monsoon to establish over the southern Arabian Sea.
After the likely onset over south Andaman and Nicobar islands, we expect the easterlies at 150-200 hPa to further extend till Sri Lanka and Maldives region by around 18th May. Combined with stronger low level westerlies, this would signal Monsoon conditions establishing over these regions by 18th-20th May.
The Somali Jet would also develop by that time and conditions could become favourable for Kerala onset of the Arabian Sea branch by around 26th May.
Verified & approved by Rajesh