Monsoon 2023 has been dangling for the last about 10 days, keeping the forecasters on tenterhooks. A large deficit of 11% rainfall of long period average(LPA) at the start of the month has now been shrinking. However, the recovery has been rather slow and taken nearly 3 days to reduce the margin by 1%. The shortfall stayed at 8% between 17 and 19 September, 7% on 20th and 21st September and now 6% between 22 and 24 September. Any shortfall of more than 4% of LPA is considered below normal for the season.
The month of September started on a dwindling note and a deficit of 11% rainfall persisted till 08th September. Courtesy, successive monsoon systems over the Bay of Bengal, there was a decent recovery with daily rainfall mostly above the average and that too by a big margin on half of the occasions. Total rainfall between 01st June and 24th September is recorded at 796.4mm against the normal of 843.2mm, deficit of 46.8mm, amounting to 6% of LPA.
Earlier, there was a large intra-seasonal variation during the first three months of the season, as well. The onset month of June remained 10% below the normal. This shortfall was made up in July when the month accumulated a surplus of 13% rainfall. The monsoon rainfall was 105% of LPA at the halfway mark of the season. And then, there was a collapse. With prolonged break-monsoon conditions, the core monsoon month of August slumped miserably to be the lowest on record since the time record-keeping began. 35% shortfall in August nearly dragged the season to the brink of a drought. However, against all hopes, remarkable recovery commenced in September and the season could be freed from the scare of yet another drought. Indian Ocean Dipole (IOD) and Madden Julian Oscillation (MJO) together, battled El Nino to soften its influence.
The southwest monsoon is still keeping the secret to itself. Rainfall activity seems to be reduced in comparison to the last week, between 17th and 24th September. Nearly 2% of rainfall needs to be offset in the remaining 6 days of the month, for the monsoon season to turn ‘normal’. Not impossible but not without struggle. The southwest monsoon is poised to finish either at the highest end of ‘below normal’ or the lowest limit of ‘normal’.