The India Meteorological Department (IMD) forecasts light to moderate rainfall across northeastern and eastern India in the coming hours.

Specifically, Sikkim and adjacent areas of sub-Himalayan West Bengal, western Arunachal Pradesh, western Assam, and Meghalaya are expected to experience rainfall, with occasional intense spells likely. 

Additionally, IMD predicts thunderstorms accompanied by lightning in extreme northeast Bihar over the next three hours. 

"Light to moderate rainfall at most places with occasional intense spells of rainfall is very likely to continue over Sikkim & adjoining areas of sub-Himalayan West Bengal, West Arunachal Pradesh, West Assam and Meghalaya and light to moderate rainfall accompanied with thunderstorm, lightning also likely over extreme northeast Bihar during next 3 hours." 

Earlier, IMD had warned of heavy to very heavy rainfall, with isolated extremely heavy falls, continuing over Sub-Himalayan West Bengal, Sikkim, and Northeast India for the next 4-5 days. 

The department also issued a heatwave warning for northern India, indicating that heatwave to severe heatwave conditions are likely to persist over the region for the next 4-5 days.