P. Reghu Ram

Current observations
The north west end of the monsoon trough may shift slightly north of its normal position while the south -east end may tilt more southward with height due to temperature gradient.

Fresh monsoon low

A fresh mid tropospheric low may lie embedded in the monsoon trough and may lie over north Rajasthan and may extend over BoB off Odisha coast around 2nd September and propagate westwards . An upper air circulation may lie over west Madhya Pradesh. A north- south shear zone may lie extending from interior Maharashtra to interior Karnataka from 1 st September. A moderate equatorial Rossby wave activity is likely around 3rd September . The east- west monsoon shear zone may lie from west Rajasthan to Odisha.

How the rains are going to impact the Onam days

Under the influence of these factors, though the rains would remain in active mode in north- west and central India, in Kerala rains which picked up momentum from 26 thAugust would continue but with lesser intensity.

Prediction for the upcoming Onam days

The offshore western monsoon trough is likely to remain active along the western coast till mid September. This would mean that the rains in Kerala may continue though the intensity may be less.

Hence scattered rains may be expected from 1st September mostly in north Kerala and central Kerala. In south Kerala, particularly Kollam & Thiruvananthapuram, except for occasional spells of rain accompanied by lightning & thunder in the eastern ranges, not much rain is likely.

On 2nd September , more rains are likely in Kannur and Kasaragod , Kozhikode, Wayanad regions with moderate showers in the eastern.pockets of central Kerala.

On 3 rd September, the rains would be moderate over the Malabar coastal region and heavier over the eastern pockets of Kasaragod, Kannur , Wayanad, Ernakulam, and Idukki.

On 4 th September, however, rains are likely to be more heavy and widespread throughout Kerala. Most of the coastal regions from Kasaragod to Kollam may receive moderate to heavy rains.The rains would be heavier in the Malabar regions of Kasaragod, Kannur, Kozhikode , Wayanad, Malappuram, Palakkad and Trichur and the eastern pockets of Ernakulam, Idukki and Kottayam .

The maximum impact of rains may be particularly in pockets like Kannur city, Koothuparamba, Mattannur, Vadakara, Balusserry, Kodencherry, Perambra , Naduvannur, Kozhikode city, Tirur, Ponnani, Iringalakkuda, Chalakkudy, Thrissur and in Kothamgalam, Moovattupuzha , Idukki, Munnar, Erattupetta, Poonjar, Kanjirappally and Ranni, Punalur .

Thiruonam day

On September 5 th, the Thiruvonam day, the rains are likely to be more in the Malabar region and the eastern ranges with heavier rains in eastern pockets of Thrissur, Ernakulam and Idukki.

On 6 th September the trains may be much lesser and restricted to the eastern pockets of Kannur, Wayanad & Kozhikode.
The rains would peter off from 7 th but may not stop entirely until 15 th September as per data analysed now.

Likelihood of rains in other major Indian cities during Onam days

In Chennai , generally cloudy skies with light rains likely on 2 nd and 3 rd September mainly in Vellore and Kanchipuram areas. On 4 th & 5 th September no rains are likely.

In Bengaluru, & Mysuru, moderate to heavy rainfall may be expected on 2 nd September . On 3,rd, 4 thn& 5 th not much rainfall activity is expected.

In Hyderabad, rains are likely on 2nd & 3rd September, but from. 4 th to 6 th September overcast skies with isolated short spells of rain may be expected.

In Mumbai and suburbs, moderate to heavy rains may be expected on 5 th & 6 th September.
In Pune , except for occasional spells of light rain not much rainfall activity is expected.

In Ahmedabad and Vadodara, heavy rains are likely on 5 th & 6 th September.

In New Delhi and Noida regions, moderate to heavy rains in short spells may be expected on all days from 2nd to 6 th September.

In Kolkata, expect rains on 2 nd & 3 rd September. However, not much rain is likely from 4 th to 6 th September.

The entire Metbeat Weather team wish all its followers and supporters a very happy and blissful Onam . Sarve Bhavanthu Sukhinaha: (Brihadaryakopanishad) Let there be peace and happiness for all living beings on the earth.