The Met department has said that the arrival of the monsoon over the coast of Kerala is likely to be delayed by a week, possibly more.
The normal date of arrival is June 1. So the Met department’s prediction is that it is likely to arrive on June 7, with the possibility that it could come four days ahead or beyond that date.
The monsoon’s arrival on the Kerala coast signals the start of the four-month season that brings more than 75 per cent of the country’s annual rainfall. India receives about 116 cm of rain every year, out of which about 89 cm comes in the monsoon season.
For a country experiencing extreme heat, drought and a severe drinking water crisis in many regions, the news of this delay can be a major mood dampener. Especially since, last month’s upbeat forecast of above normal rainfall this monsoon season had made people look forward to June.
However, the date of the arrival of the monsoon has little bearing on, and is largely inconsequential to, the amount of rainfall that is received during the season. Late arrival does not mean less rains during the season or vice-versa.
Last year, for example, the onset of monsoon happened two days in advance and it rained heavily for about a week or ten days after that, but the season still ended up producing 14 per cent less rains.
The Indian Meteorological Department’s prediction of the monsoon arrival on Sunday does not change its rainfall forecast for the season. The IMD has said the country as a whole will receive 106 per cent of normal rainfall this year, with a model error of 5 per cent.
Late arrival also does not mean the monsoon will be late in other regions of the country. The speed with which monsoon spreads over the country after hitting Kerala depends on many local factors like the creation of low-pressure areas.
The arrival, or onset, of the monsoon over Kerala is a single event. Due to this, there is a greater degree of uncertainty about it happening on any given date.
Also, the onset is declared on a pre-defined criteria. The monsoon is declared to have set in over Kerala only if at least 60 per cent of the meteorological stations in the state record 2.5 mm or more of rains for two consecutive days. Thus, it is quite possible that Kerala has 2 mm rainfall through most of the first week of June and but still it won’t the monsoon will not be said to have arrived.
The significance of the delay in the monsoon onset is only in the short term. The wait for rains is going to get prolonged. For a country that is desperately awaiting rains, this is bad news no doubt but in the long run this delay might be of little significance, if not entirely inconsequential.