




As you can see from the Dam levels in last week of July 2020, there has has been huge improvement in most of the dams with most dams in Coimbatore reaching full level. Mettur is close to 70% full and with all 4 dams in Cauvery basin in Karnataka being 100% full, all the excess water will be coming steadily to Mettur Dam in the coming days.
Mullaperiyar Dam level created little bit of panic, but rains subsided right on time and there is no need to panic on the Dam levels again for the time being. The water from Periyar Dam will be transferred to Vaigai Dam. Steady increase in Vagai Dam can be expected in next one month.
With dry days ahead, there will not be much to expect in the dam levels in the next two weeks. The Then Pennai basin dams of Sathanur and Krishnagiri are a worry, September and October are key month for them. Hope there is some improvement seen there.
Chennai combined levels are one of the best considering August with monsoon ahead, we are rightly placed. Even a 80% of monsoon rains can be good improvement to levels in Chennai lakes.
Next Active Spell of rains for Kerala, Cauvery Catchment and Western Ghats might start in around Mid-September. Till then rains will happen here and there with occasional isolated heavy rains.
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Well the North East Monsoon type rains will continue for next 2 days with an UAC located in SW bay and pushing convergence in the north will seen over Central Coastal Tamil Nadu to South Tamil Nadu particularly in parts of Delta region (Nagapattinam, Tiruvaraur, Thanjavur) and South Tamil Nadu regions (Ramanthapuram, Sivagangai, Pudukottai, Nellai, Thenkasi Kanyakumari, Thoothukudi) and even other nearby areas.
Reason for rains
There is an Upper Air Circulation (UAC) in South West of Sri Lanka and as a result the convergence of easterlies are happening over North East Sri Lanka and Delta to South TN coast. Typical monsoon rains.
Good Rains are expected in next 2 days in Nagai, Thanjavur & Tiruvarur districts and moderate rains in Tuty, Ramanathapuram, Nellai, Kanyakumari, Thoothukudi, Pudukukottai, Cuddalore, Thenkasi, etc. Light rains are possible in Nilgiris and Coimbatore district too.
Is this the last rains for the month ?
No No, we already informed that monsoon will extend into February this year and more rains will start from month end around January 29/30, 2021. Breaks in North east monsoon are common. So there will be break in rains from 22nd January only to start again in 29/30th January. So the all time record rainfall in January is going to be broken for sure.
Tamil Nadu All time Top January Rainfall years under threat
in mm (100 mm and above)
Normal for TN in January is 18 mm
1921 – 141.2
2021 – 137.7 (till 20.01.2021) – High chance to break the ATR, 2021 deserves to be in No.1
1923 – 136.0
1920 – 135.9
1909 – 116.5
1943 – 112.0