Withdrawal of Southwest Monsoon from entire West Bengal & Sikkim and other adjacent states

KalimNews, October 13, 2024 : Southwest Monsoon has further withdrawn from remaining parts of Bihar, Jharkhand, entire West Bengal & Sikkim; some more parts of Chhattisgarh, Madhya Pradesh; many parts of Odisha and some parts of Assam & Meghalaya, northwest Bay of Bengal. 

The line of withdrawal of Southwest Monsoon now passes through 28.5°N/89.5°E, 27.0°N/90.0°E Dhubri, Tura, 22°N/89°E, 20°N/87°E, Gopalpur, Raipur, 22.5°N/79.5°E, Khargone, Nandurbar, Naysari and 20°N/70°E. 

Conditions are favourable for further withdrawal of Southwest Monsoon from remaining parts of Gujarat, Madhya Pradesh, Chhattisgarh, Odisha & some more parts of Maharashtra and north Bay of Bengal during next 2 days. 

Thereafter Southwest Monsoon likely to withdraw remaining parts of the country during subsequent 2 days. Simultaneously with the setting in of easterly & northeasterly winds over southern peninsular India, south & adjoining central Bay of Bengal, the Northeast Monsoon rainfall activity is like to commence over south eastern peninsular region during the same period. 

Weather Systems: 

The Well Marked Low pressure area over eastcentral & adjoining westcentral Arabian sea persisted over the same region at 0830 hours IST of today, the 13th October 2024. It is likely to move west-northwestwards and intensify into a Depression over central Arabian Sea during next 12 hours. 

The upper air cyclonic circulation over southwest Bay of Bengal now lies over north interior Tamil Nadu in lower tropospheric levels tilting southwestwards with height. 

A trough runs from centre of the Well Marked Low pressure area over eastcentral & adjoining westcentral Arabian sea to Comorin area across south Kerala and the cyclonic circulation over Tamil Nadu in low to mid tropospheric levels. 

The cyclonic circulation over southeast Bay of Bengal and adjoining equatorial Indian Ocean moved west- northwestwards & lay over southeast Bay of Bengal and extending upto 5.8 km above mean sea level at 0830 hours 1ST of today, the 13th October 2024. Under its influence, a low pressure area is likely to form over central parts of south Bay of Bengal around 14th October. It is likely to become Well marked low pressure area and move west-northwestwards towards north Tamilnadu, Puducherry and adjoining south Andhra Pradesh coasts during subsequent 48 hours. 

The upper air cyclonic circulation over east Assam & neighbourhood persists in lower tropospheric levels. 

Forecast & Warnings (upto 7 days) : 

South Peninsular India :

Fairly widespread to widespread light to moderate rainfall very likely over Tamil Nadu, Puducherry & Karaikal, Kerala and Mahe, Lakshadweep, Karnataka; Scattered to Fairly widespread light to moderate rainfall over Coastal Andhra Pradesh & Yanam, Rayalaseema; Isolated to Scattered light to moderate rainfall very likely over Telangana during the week. 

Isolated extremely heavy rainfall very likely over Tamil Nadu, Puducherry & Karaikal, Rayalaseema on 16th October. 

Isolated very heavy rainfall very likely over Tamil Nadu, Puducherry & Karaikal during 13th-17th; Kerala & Mahe on 17th & 18th; Coastal Andhra Pradesh & Yanam on 15th & 16th; Rayalaseema during 15th -17th; Coastal & South Interior Karnataka on 17th October. 

Isolated heavy rainfall very likely over Kerala & Mahe during the week; Coastal Andhra Pradesh Si Yanam, Rayalaseema during 13th-17th; Rayalaseema during 14th-17th Coastal & South Interior Karnataka during 15th-18th; North Interior Karnataka on 17th & 18th October. 

West & Central India : 

Scattered to Fairly widespread light to moderate rainfall very likely over Gujarat State during 2 days; Isolated to Scattered light to moderate rainfall over same region during subsequent 5 days; Isolated to Scattered light to moderate rainfall over Konkan & Goa, Madhya Maharashtra, Marathwada, Madhya Pradesh, Vidarbha, Chhattisgarh during the week. ✓ Isolated heavy rainfall very likely over Madhya Maharashtra, Gujarat State, West Madhya Pradesh on 13th; Konkan & Goa on 17th October. 

Northwest, Northeast & East India: 

No significant rainfall likely over these regions during the week. 

(i) Northeast Monsoon rainfall activity is like to commence over south eastern peninsular India

around 15-16th October.

(ii) The Well marked low pressure area over eastcentral Arabian sea is likely to move westnorthwestwards and intensify into a Depression over central Arabian Sea during next 12 hours.

(iii) A low pressure area is likely to form over central parts of south Bay of Bengal

 around 14th October.

 (iv) Isolated very heavy to extremely heavy rainfall likely over Tamil Nadu and  Andhra Pradesh during 15-17th October.

❖ Conditions are favourable for further withdrawal of Southwest Monsoon from remaining parts of Gujarat, Madhya Pradesh, Chhattisgarh, Odisha & some more parts of Maharashtra and north Bay of Bengal during next 2 days.

❖ Thereafter Southwest Monsoon likely to withdraw remaining parts of the country during subsequent 2 days.

Simultaneously with the setting in of easterly & northeasterly winds over southern peninsular India, south & adjoining central Bay of Bengal, the Northeast Monsoon rainfall activity is like to commence over south eastern peninsular region during the same period.