Weather watch. Bay of Bengal may stay active for a fortnight, support monsoon conditions 

Global model forecasts suggest the Bay of Bengal would stay active right into the last week of July, thanks to incremental monsoon flows inward and across Indochina from South China Sea/West Pacific and formation of helpful cyclonic circulations/low-pressure areas in the process.

US Climate Prediction Centre points to the likelihood of formation of a cyclone over West Pacific moving towards South China Sea, capable of sending flows into the Bay, and supporting rain over East India during July 12 to 18. This will likely continue into the subsequent week (July 19 to 25), keeping West Bengal, Odisha, Jharkhand, Chhattisgarh and parts of East Madhya Pradesh wet. 

Cyclonic circulations 

US National Centre for Environmental Prediction is of the view the rainfall regime may filter into adjoining Central India and North-West India, apart from the West Coast. This phase would likely be overseen by cyclonic circulations/‘lows’ as they form in the Bay and track into these regions. India Meteorological Department (IMD) has hinted in its numerical weather predictions about intense activity around the West Bengal coast from July 14 to 17, likely throwing up these systems. 

Rains for East India 

An IMD outlook issued on Friday and valid for next five days said East and adjoining North-East India will witness fairly widespread to widespread light to moderate rainfall with isolated heavy to very heavy rainfall across the hills of West Bengal and Sikkim, Assam, Meghalaya, Arunachal Pradesh, Nagaland and Manipur. Isolated heavy rainfall is likely over Odisha during next five days; Bihar for three days from Sunday; and Jharkhand on Tuesday. 

All-India rain deficit shrunk significantly during the last 24 hours to 3 per cent. This is attributed to sustained rainfall over the West Coast, West and North-West India. Some Met Divisions in Central India and South India saw some swing-back to positive anomalies, helping trim the deficit. These included Marathwada, Chhattisgarh, Coastal Karnataka, South Interior Karnataka, Kerala and Lakshadweep. 

Positive rain anomalies 

The rain-deficient Central India will see light to moderate to fairly widespread to widespread rainfall with isolated heavy rainfall on Saturday and Sunday. This is even as the overarching shear zone of monsoon turbulence moved closer to the region. The crucial monsoon trough over land remained ideally south of its normal position while the offshore trough ran from Gujarat to Kerala coast. 

Elsewhere, a land-based cyclonic circulation hung over Jharkhand, while an enduring twin was located over North-East Arabian Sea and adjoining Gujarat. It is into this vibrant setting an incoming western disturbance is bracing to slot itself in. On Friday, it was in the process crossing the international boundary and entering extreme West Rajasthan. 

West Coast rain trend

Light to moderate widespread rainfall with isolated heavy to very heavy rainfall over South India. Over West India, light/moderate widespread rainfall with isolated heavy to very heavy falls may continue over Konkan, Goa, ghat areas of Madhya Maharashtra on Saturday. Similar conditions would persist over Gujarat for next four days, and isolated extremely heavy falls over Saurashtra and Kutch on Saturday. 

Rain for North-West

Over North-West India, light to moderate fairly widespread to widespread rainfall with isolated heavy rainfall is likely during next 4-5 days. Isolated very heavy rainfall likely over Uttarakhand until Sunday; over Jammu & Kashmir and Himachal Pradesh on Saturday and Sunday; over Punjab and Haryana on Saturday; and over Uttar Pradesh on Monday and Tuesday.