Conditions are favourable for the onset of the South-West monsoon over Kerala in the next 48 hours, the India Meteorological Department (IMD) has said. 

The monsoon will “further advance” over parts of the south-west Arabian Sea, parts of the south-east Arabian sea, south and east-central Bay of Bengal and parts of the north-east Bay of Bengal, the IMD said on Wednesday. 

The IMD has predicted that there will be “no significant” heatwave conditions over the next five days.

The IMD’s monsoon update is in line with forecasts that had predicted India’s most-watched weather event around May 27, some five days before the scheduled date of June 1 for its arrival. 

Trough’s influence

Scattered to fairly widespread light or moderate rainfall is likely over the north-east under the influence of a trough from east Bihar to north coastal Andhra Pradesh and southwesterly winds from the Bay of Bengal to the north-east and adjoining east India in lower tropospheric levels.

The IMD projected isolated to scattered rainfall with isolated thunderstorms or lightning or gusty winds over Bihar, Jharkhand, Odisha and West Bengal and Sikkim over the next five days.  

Isolated heavy rainfall is likely over Arunachal Pradesh and Nagaland, Manipur, Mizoram and Tripura on Wednesday and Sunday; and over Assam-Meghalaya over the next five days barring Friday.

The national weather forecaster said under the influence of a north-south trough and westerly winds from the Arabian Sea over south peninsular India in lower tropospheric levels, widespread light or moderate rainfall with thunderstorms or lightning is likely over Kerala, Mahe and Lakshadweep.  

Squally weather over SW Arabian Sea

Isolated to scattered rainfall over Andhra Pradesh, Telangana, Karnataka and Tamil Nadu, Puducherry and Karaikal during the next five days. Isolated heavy rainfall is also likely over Tamil Nadu on Thursday.  Squally weather (wind speed 40-50 kmph gusting to 60 kmph) is likely over the southwest Arabian Sea during next five days and over the north-east Arabian Sea and adjoining Gujarat coast during May 27-29. Scattered light or moderate rainfall with isolated thunderstorm/lightning/gusty winds is very likely over Jammu and Kashmir, Himachal Pradesh under the influence of a fresh approaching western disturbance.

The influence will also result in isolated rainfall over Uttarakhand, Punjab, Haryana, Chandigarh and Delhi, Uttar Pradesh and Rajasthan during the weekend. Dust storm activity at isolated places is likely over West Rajasthan on during the weekend.