The southwest monsoon hits Bihar through Purnea district of the state. The north eastern districts of the state including Araria, Purnia, Supaul and Kishanganj are witnessing widespread rains. Vivek Sinha, director of Patna Meteorological Centre, said conditions are favourable for. further advancement of monsoon into some more parts of Bihar during the next four to five days. Meanwhile met office has issued yellow alert for thunderstorm with lightning in northern parts of the state today and most parts of Bihar from tomorrow to Friday.