A view of the grey sky as the national capital witnesses a drastic shift in weather conditions after heavy rain and severe thunderstorms, in New Delhi on Friday. (Source: ANI)India’s southwest monsoon is set to advance further across large parts of the country over the next four to five days, bringing widespread rainfall to several regions even as heatwave conditions continue in pockets of central India, the India Meteorological Department (IMD) said.According to the latest weather bulletin, IMD has forecast isolated heavy to very heavy rainfall over Sub-Himalayan West Bengal and Sikkim, Arunachal Pradesh, Assam and Meghalaya during the next six to seven days, raising the possibility of localised flooding and disruptions.Monsoon to cover more statesAccording to the weather department, conditions are favourable for further advance of the southwest monsoon into more parts of Maharashtra, the remaining areas of Karnataka, Telangana, Andhra Pradesh, West Bengal, Odisha, Jharkhand, Bihar and parts of south Chhattisgarh during the next four to five days.Widespread rainfall is expected across northeast India, the eastern Himalayan region and parts of southern India, while scattered showers are likely over northwest and central India.Delhi weather updatesThe national capital is expected to experience partly cloudy skies with chances of thundery development over the next two days.On Monday, very light to light rain accompanied by thunderstorms, lightning, and strong winds of 40-50 kmph, gusting up to 60 kmph, is likely across Delhi-NCR, including Noida, Ghaziabad, Gurugram and Faridabad, particularly during the afternoon and evening.Similar conditions are expected on June 16, although rainfall activity may be less widespread. By June 17, skies are likely to remain partly cloudy with temperatures rising further.Story continues below this adThe maximum temperature in Delhi is expected to range between 38 degrees Celsius and 40 degrees Celsius on Monday and may rise to 40 degrees Celsius to 42 degrees Celsius by June 17.Heavy rain alert for Northeast and East IndiaNortheast India is likely to witness the most intense rainfall this week.The IMD has forecast isolated heavy rainfall over Arunachal Pradesh, Assam, Meghalaya, Nagaland, Manipur, Mizoram and Tripura. Very heavy rainfall is likely over Arunachal Pradesh during June 17-18 and over Assam and Meghalaya during June 17-19.In eastern India, Sub-Himalayan West Bengal and Sikkim are expected to receive heavy rainfall on June 15 and June 20, with very heavy rainfall likely from June 16 to 19. Bihar may also receive heavy rainfall on June 16.Story continues below this adThunderstorms accompanied by gusty winds reaching up to 60 kmph are expected across Bihar, Jharkhand, Odisha and West Bengal during the forecast period.Thunderstorms and squalls over northwest IndiaSeveral parts of northwest India, including Rajasthan, Punjab, Haryana, Delhi and Uttar Pradesh, are likely to witness thunderstorms and strong winds over the coming days.Thundersqualls with wind speeds of 60-70 kmph, gusting up to 80 kmph, are forecast over Rajasthan on June 15, while duststorm conditions are also likely over western Rajasthan.Rainfall activity is expected across Jammu and Kashmir, Ladakh, Himachal Pradesh and Uttarakhand through June 20.Story continues below this adSouth to receive widespread rainfallKerala, coastal Karnataka and adjoining regions are expected to receive widespread rainfall during the week, with isolated heavy showers likely over Karnataka, Telangana and Tamil Nadu.Heavy rainfall is forecast over Tamil Nadu and Puducherry on June 16 and 17, while Telangana may witness heavy showers between June 18 and 20. Strong surface winds are also likely over Rayalaseema during June 15-18.HeatwaveDespite the advancing monsoon, heatwave conditions are expected to persist in isolated pockets of Marathwada from June 15 to 17 and in Vidarbha on June 15 and 16.The IMD has also warned of hot and humid weather over Konkan, Goa and Madhya Maharashtra through June 17. Warm night conditions are likely in isolated areas of Konkan and Goa on June 15 and 16.