Pre monsoon showers usually make an appearance over the city of Mumbai during the last few days of May. Monsoon makes an onset over the commercial capital of the country on June 10.
However this time, since the onset has coincided with the storm in the Arabian Sea, there is likely to be a delay in rains. This year, there has been no measurable rain in May. Even in the first week of June, traces of rain has been recorded.
The onset of monsoon over the Indian mainland has been delayed and has yet not made its entry into Kerala. Mumbai will also see a delay in the arrival.
Pre Monsoon showers are expected over Mumbai on June 9, 10 and 11. More showers are expected thereafter. As far as the storm is concerned, when Biparjoy moves abeam Mumbai, it will still be at a distance of 700 km, which is too far to give any significant impact.