Southwest monsoon has literally struggled to establish itself over South Peninsula this season so far. In the first phase, the monsoon travels from south to north to cover the complete peninsula in about 10 days' time. By 15th June, it reaches South Coastal Gujarat, the entire Maharashtra, half of Chhattisgarh, Bihar, Jharkhand and the entire Odisha & West Bengal.
From its earlier date of 10th June, as per revised dates, the monsoon reaches Mumbai on 11th June. The western arm of the monsoon is stalled since 11thJune when it reached Ratnagiri and has not moved an inch thereafter. Even the eastern arm is stagnant for the last week.
Monsoon arrived over Kerala with a delay of one week. Further progress was weak and sluggish. Rainfall deficiency over most southern states has mounted to 70-80%. Further up, Maharashtra has witnessed a large deficit of 80-90%. Most parts of Konkan have observed extremely poor monsoon rains till now. The financial capital Mumbai is nearly starved in the first 3 weeks of June.
Mumbai receives about 526.3mm of average rainfall in June. More than halfway through the month, the city has measured only 17.1mm so far. Few showers have been recorded in the last 7 days with a maximum of a mere 6 mm in 24 hours. One more week will not be any different and showers are going to be far and few.
Mumbai observed the most delayed monsoon on 27th June in the year 2009. Coincidentally, this delay was attributed to the El Nino, phenomenon of warm Pacific Ocean waters during monsoon months. 2nd longest delay since 2009 was in 2019 when the monsoon reached on 25th June.
In 2016 also, the monsoon made delayed arrival on 20th June. In addition, the monsoon in Mumbai also got delayed in 2012, 2014 and 2015 due to El Nino like conditions. Monsoon knocked at Mumbai a little before time on 09th June 2018. Mumbai has only received sporadic and fleeting showers so far. Though the criteria like onset over Kerala satisfying rainfall, clouds, OLR and speed and depth of westerly winds were fulfilled last week, typical monsoon rains have given amiss. Monsoon arrival over Mumbai is never without the submerging showers disrupting normal life.
This year, to start with, the monsoon arrived late over Kerala and was later deranged by cyclone Biparjoy. It is almost similar to 2019 when the monsoon landed on 25th June. This was one of the most delayed arrivals in the last 45 years. The monsoon was stalled by cyclone ‘VAYU’ which was similar to ‘BIPARJOY’ in track, timings and intensity. However, the storm had weakened over the sea and did not make any significant landfall over Gujarat. Prior to that, another cyclone ‘NAUNAK’ in 2014 over the Arabian Sea had corrupted the monsoon onset.
Cyclone Biparjoy has weakened to a depression. Remnant of the cyclone continues to give downpours over Rajasthan and is likely to extend reach up to North Madhya Pradesh for the next 72 hours. The weather system is likely to get filled up over the same region and make way for the advance of the monsoon. There is the likelihood of monsoon system forming over the Bay of Bengal during the early 4th week of June.
The first monsoon system of the season over the Bay of Bengal will push the monsoon deep inland after the 25th of June. This weather system will take the rains to parched areas of Maharashtra and the other central parts. This feature will also accentuate the monsoon surge along the West Coast, more so for the Konkan region. Mumbai can expect one of the most delayed monsoon coinciding with the earlier record date of 27th June. Heavy rains are likely for 2-3 days commencing 27th June and lasting till fag end of the month.
