This year, Monsoon has had a delayed onset over the mainland while Monsoon was early in the Bay islands. Currently, the Monsoon is sluggish and week and very poor in terms of advancement. Northeast India usually gets Monsoon rains by June 5, but this time, they were ten days late. Monsoon onset over South India is also delayed.
The only hope for the revival of Monsoon is the upcoming low pressure area in Bay around June 20 and 21, which will facilitate westerly flow right up to the Indian Ocean. Currently, Monsoon is deficient by 43 percent, and is likely to be deficit for the next four days, as daily rains will be below normal.
Thus, within the next four to five days, Monsoon 2019 may revive its advancement all thanks to the coming Low Pressure Area.
Westerly winds in the Arabian Sea during this time are important. The intensity and performance of Monsoon is gaged through direction and speed of westerly winds in the Arabian Sea. Initially, westerlies did set in, but thereafter Cyclone Vayu came, and it squeezed moisture within its periphery. These Cyclones in the Arabian Sea are not kind to Monsoon. Monsoon skirted Saurashtra wherein Gujarat missed the heavy rains. Now also, it has weakened into a well marked low pressure area and is likely to hit Kutch.
The further advancement of Monsoon is still sluggish, winds over Lakshadweep, Kerala, Comorin are westerlies instead of south-westerlies which is not good for the pace of Monsoon and does not look good for the next few days.
For the last three years, Monsoon has behaved differently. In the years 2017 and 2018, Monsoon has had a timely onset with 2018 seeing onset over Kerala on May 29 and 2017 on May 30. During both these years, after making initial advancement for a week or ten days, Monsoon progress was stalled.
Monsoon did not advance after Mumbai on the West Coast and Bihar on the eastern side. Thus, Monsoon remained stagnant from June 10 to June 21 in 2018 and stalled between June 12 to 23 in 2017.
Prior to that in 2016, onset was on the same date. However, in spite of early set in, progress was late initially only with the entire Monsoon advancing a week late.