After cyclone Biparjoy dissipated, the southwest monsoon seems to be making a vengeful comeback. The skies opened up in such a sustained and intense manner, especially in the first week of July, that the Indian Meteorological Department declared a marginal monsoon surplus in India on July 9.
Kerala, which had witnessed a 60.75% monsoon deficit in the first four weeks of the season, has also seen a dramatic revival. There is not yet a surplus but the deficit, on July 10, has shrunk by more than half, to 29%.
By now, five districts (Alappuzha, Kannur, Ernakulam, Kollam and Pathanamthitta) have recorded normal rainfall. At this stage, Idukki and Wayanad are going through the driest stretch with a rainfall deficit of 50 and 53%.
The fifth-week monsoon surge was felt most in Alappuzha and Kollam, with an excess rainfall of 118 and 113% respectively. Other districts that saw a huge precipitation during the fifth week were Pathanamthitta (108%), Kottayam (92%), Ernakulam (78%) and Thiruvananthapuram (68%).
The monsoon resurgence was not uniform across Kerala. Notably, the five districts - Wayanad, Palakkad, Idukki, Kozhikode and Malappuram - that had suffered the highest rainfall deficit during this season have experienced the lowest rains even in the week (June 29 to July 5) that saw the monsoon regain its fury.
Wayanad had the worst deficit in the first four weeks: 76.5%. And during the sumptuous fifth week, too, the district had a huge deficit of 40%. In the same fifth week, Alappuzha and Kollam received a surplus of 118 and 113%. At this moment, Wayanad has a rainfall deficit of 53%.
After Wayanad, it was Kozhikode that had suffered the worst deficit in Kerala till the end of the fourth week of the season: 75%. It, too, had a deficit of 5%. On July 10, the district's deficit is still a high 47%. This is a slight improvement because, on July 5, the deficit was 60%.
Palakkad, Idukki and Malappuram are the other big deficit districts during the first four weeks: 75%, 70.4% and 68.75% respectively. These districts, too, had deficit rainfall during the fifth week when the southwest monsoon was on a revival path. Now, their rainfall deficits are 41% (Palakkad), 50% (Idukki), 30% (Malappuram).
After these five districts, it was Kasaragod that had witnessed the poorest rainfall till the end of the fourth week of the season: 67%. In fact, Kasaragod had suffered the worst week in the season in the whole of Kerala. The first week of the monsoon saw a nearly 100% rainfall deficit in the northernmost district; the worst dry spell so far this season.
However, Kasaragod received bountiful rains in the fifth week, a surplus of 57%. On July 10, after a surplus week, the district's deficit has dwindled to 20%.
For the whole of June there was just one day, June 28, when the daily rainfall shot above the average mark of 20 millimetres. For a monsoon to be called an active spell, daily rainfall has to cross the average mark for at least three consecutive days.
The change of month saw a sudden change in the monsoon's character. From July 3, the daily rainfall shot far above the average mark for six consecutive days till July 9, touching a high of 90 mm on July 6.
In 2019 and 2020, when Kerala officially had normal southwest monsoon, there was rainfall deficit in June. It was 35% in 2019 and 20% in 2020. Nonetheless, 2019 witnessed floods because of the massive precipitation during August. In 2020, too, there was a monsoon surge in August.
At this point, the water level in all major dams in Kerala are below even the acceptable levels, forget the maximum levels.
For instance in Idukki dam, Kerala's largest, the water level on July 10 is 2320.9 feet. The maximum level that can be accommodated on the day is 2375.33 feet. The lowest level of alert, the blue alert, will be issued only when the level touches 2367.33 feet. A red alert will be issued when the water level touches 2374.33 feet.
