Mumbai sees highest June rainfall in six years

The city has received a total of 967

The city has received a total of 967.7mm rain in June so far, making it the highest rainfall received during the month in six years. It also marks a 90% departure from the monthly normal rainfall of 505mm. Data available with the India Meteorological Department (IMD) shows that 706mm of rain was recorded in the first 12 days of the month alone.

HT Image

The heaviest showers in June occurred on June 9 when the city saw 220.6mm or 44% of the monthly normal rain in just nine hours. This marked an early onset of the monsoon two days prior to the official onset date of June 11. The presence of a low-pressure area in the Bay of Bengal around that time along with a cyclonic circulation in the Arabian Sea intensified showers along the entire Konkan coast with intense westerly winds gusting at between 50kmph and 60kmph.

However, there has been a sharp decline in the intensity of rains since then, with the southwest monsoon being in a subdued phase which, IMD officials say, is likely to continue for another week. “Models suggest monsoon entering into a break spell from June 29. Heavy rains to be confined mainly over northeast India at least till July 5 with suppressed rainfall over rest of India. Active break spells are part of monsoon dynamics and decide quantum of seasonal rainfall,” ministry of earth sciences secretary M Rajeevan had tweeted earlier this week. Speaking to HT on Wednesday, Rajeevan said models show a sign of monsoon revival sometime around July 7.

The Monsoon Intraseasonal Oscillation and Madden-Julian Oscillation were not active over India, thereby suppressing rainfall. After June 12, there were no large scale weather features to support continued effects of monsoon. Cross-equatorial flows remained weak, there was an absence of convection over the Arabian Sea and Bay of Bengal, and strong mid-latitude westerly winds — all of these played a part in weakening monsoon.

Mumbai had recorded just over 340mm rain in June 2020, 515.1mm in June 2019, 792.5mm in 2018, 523.2mm in 2017, 695.2mm in 2016, and 1,106.7mm in 2015, shows IMD data. During June 2014, Mumbai witnessed its lowest June rainfall in 10 years at 87.3mm while the second lowest was in June 2012 at 298.5mm. The all-time lowest June rainfall was in 1972 at 0.2mm followed by 1995 at 82.2mm.

In June this year, Mumbai is among five Maharashtra districts that has seen ‘large excess’ rainfall, which is over 60% of the seasonal normal. Another 16 districts in Vidarbha, Konkan, and Madhya Maharashtra saw ‘excess’ rainfall with 20% to 59% of the seasonal normal; while 11 districts, largely in Madhya Maharashta, and a few in Vidarbha, saw normal rainfall. Konkan and Goa meteorological sub-division received ‘excess’ rain at 41% over normal.

Three districts — Nandurbar, Akola and Dhule — saw deficient rains ranging between -30% to -51% of the normal amount for June. However, the entire state has received ‘excess’ rainfall which is 31% above the state’s normal of 207.6mm.