Mumbai has already overshot its normal date of withdrawal of monsoon. Light to moderate rain in different parts of the city and suburbs is continuing. Though the wind pattern has changed to easterly, still patchy showers are lashing parts of the city at irregular intervals. These conditions are not ideal for announcing monsoon withdrawal. A pause of at least 2-3 days is needed to commence withdrawal and the rains under the influence of the post-monsoon system, if any, could come back later.
Currently, there is a cyclonic circulation over the Southeast Arabian Sea and Lakshadweep region. There is the likelihood of a low-pressure area forming over the same region, shortly. Proximity of the system to the Konkan Coast is pushing the strong easterly stream, all along the Konkan-Goa coastline. Infrequent and aberrant showers, with least predictability of timings, will continue over the next 4-5 days. The intensity and spread of these showers will also vary and unlikely to observe any pattern.
The southwest monsoon withdraws from the city, anytime around 06th October. Delay of a few days is not very uncommon but the factors causing the hold up are different. The main cause of averting the retreat of monsoon is the weather system in the Arabian Sea, which actually is a part of the post-monsoon feature. Since the rains are continuing with no formal announcement of withdrawal, practically the southwest monsoon season is getting prolonged. It is akin to a catch-22 situation.
Even after the current probable weather system, another one will closely follow, without any appreciable break in the rainfall activity. The successor system will retain the continuity of the unseasonal, light to moderate rains. It will be a tricky situation, for taking a final call of withdrawal of monsoon from Mumbai this season.