The arrival date is calculated seeing today's position.Further from today, we presume the normal rate of progress.This initial estimated dates are subject to some changes, and will be finalised around mid-May, when the puzzle pieces get better arranged.
(Dates in brackets are the normal dates of arrival).
As of today, there seems to be a slight delay in both, Arabian Sea and Bay Branches of the Monsoon. There continues to be a doubt on the timely arrival of the Monsoon in the Bay branch.
Arabian Sea Branch: Though there is some improvement in some of the parameters, there is still much to be achieved, and most parameters are still lagging behind time, and are -ve.
The Arabian Sea branch, now affected by the temporary "dis-organisation " in the equatorial winds at the equator, can recover provided the winds regroup fast.
On these calculations, Vagaries would maintain the Monsoon to reach Maldives around the 24th of May 2016 (20th May), Sri Lanka around 27th/28th of May (25th May).
Kerala by the 4th/5th June (1st June).
Hence, maintaining and presuming the normal rate of progress, Goa should get Monsoon rains by around 10th June (5th June). NE States can also see Monsoon resume around that date.
Mumbai by 13th/14th June (9th June). Pre Monsoon thunder showers could start from around 7th/8th June 2016.
Bay Branch: A Western Disturbance (M-1) is active the Northern regions of the sub continent, and will gain strength by the 5th and 6th. Back to back, we may see M-2 around 12th May...if it happens, may lead to a delay the formations of any Low in the Bay.
Bay branch needs to wait a few days for the the pulses from the East in the Bay to resume for Low formations.
SWM should hit South Andaman Sea around 17th.May (12th May), and rest Andaman Islands by 20th May 2016.
Generally moves up (normally) the Bay at a sustained speed, and Kolkata should see Monsoon arrival by the 11th/12th of June.
We stop at this initial progress, and work out further region wise progress at a later date (as is the usual practise in Vagaries' MWs).
These Dates are worked out and estimated as per my personal calculations and may not be used for commercial purposes.The dates are not binding on anyone and no responsibility is taken if used for any purposes.