SouthWest Monsoon 2024 Forecast for Mumbai Metropolitan Region
Date: 17 April 2024
Cities Applicable: Mumbai, Thane, Mumbai Suburban, Bhiwandi, Kalyan, Dombivali, Ulhasnagar, Panvel, Navi Mumbai, Karjat, Lonavala
Synopsis
El Nino, which was biggest concern of many people as it caused deficit monsoon in August 2023, now its subsiding. Throughout Monsoon 2024, ENSO is likely to be Neutral or Weak La Nina by September.
This indicates that ENSO will not effect much in first half, also in second half, it will effect monsoon positively by increase rainfall all over india and Mumbai in September Month.
IOD plays a crucial role in a positive monsoon in west coast. This year from June itself, a strong positive IOD is likely at +1.0© in June with maximum +1.6© in July-August.
This will result in a very positive monsoon in June-August months too. From september, IOD will start to subside but emerging La Nina will maintain a good monsoon.
Onset-Withdrawal Forecast
Monsoon onset in Mumbai is very likely on 8 June 2024 with error margin +/- 2 days.
Monsoon will make a vigorous onset not only in Mumbai, but in all parts of India under influence of Positive IOD.
Note: Due to Positive IOD influence, chances of a Cyclone is seen in Arabian Sea in May end to Early June. If such cyclone forms in that period, monsoon onset can be delayed to 15 June.
Monsoon withdrawal this year can be bit delayed due to La Nina effect. However subsiding IOD may also play a role in it.
Combination of these factor indicates that Monsoon in Mumbai will extend upto 14 October.
However this year, unseasonal rains in November-December are very likely.
Monthly Forecast
June
Due to probable early and strong onset of Monsoon, good rains will begin in Mumbai MMR from 8-10 June. Though there will be frequent breaks.
MJO pulse will mostly enter in Indian basin in month end periods, hence its likely that month end of every month will see flooding rainy days
Expected volume: 560MM
July
This is the peak monsoon month in Mumbai and will have support of Positive IOD at almost +1.6%
This will result in good rains in July.Â
MJO pulse may result in flooding rains in 3rd – 4th week of July. Second half of month likely to be more rainy than first half
Expected volume: 1700mm
August
Positive IOD will continue to surge in August month. This will result in good rains in August month too. Overall a postive month. 3rd week likely to be most wet.
Expected volume: 690mm
September
IOD will start reducing but La Nina will begin to emerge, this may result in formations of LPA in Bay of Bengal which may give rainy days in start of the month. Mid september can see some thunderstorms due to disturbed wind patterns creating UAC in arabian sea and co influence of Dry and Moist winds. End of the month will result in good rains.
A positive month for monsoon
Expected volume: 510mm
October (1 – 15 OCT)
This will be mostly associated with post monsoon t-storms which may dump more rains in less time mostly in evening hrs.
Monsoon may withdraw near 14 OCT +/- 2 days.
Expected volume: 65mm
Above Normal Monsoon likely in MMR
Total Rains in official Monsoon 2024 (1 june – 30 September): 3460mm
Total Rains in Unofficial Monsoon 2024 ( 1 June – 15 October): 3525mm
Region Wise total rainfall forecast
City areas like Santacruz, CSMIA and central mumbai: 3525mm
North Mumbai, Borivali, Suburbs, Thane, Panvel, NaviMumbai KDMC 3600-3800mm
SOBO: 2700-3000mm
Badlapur, Karjat, Khopoli: 3800-4100mm
Lonavala : 4200mm+
Very Heavy Rain Potential Days
June
8-12 June
24-29 June
July
1-5 July
18-22 July
26-31 July
August
8-13 August
25-29 August
September
3-7 September
15-19 September
26-30 September
October
N/A
T-storm may dump huge rains in short time may cause short durations water loggings in low lying areas
Thanks for Reading
Study and Analysis by
SkyWatch Weather India🇮🇳
Vedant Upadhyay
