Making nowcasting and severe weather warning by New Generation Weather Radar nee d to Start from radar observations. Different weather systems must to use diffe rent methods of radar observations. Different observation methods and different f orcast objects must to use different process methods of radar data for stressin g echo characters. Nowcasting and severe weather warning are producted on the bas is of radar echo analyses. Radar echo analyses need to grasp whole process of ec ho evolutions. Synoptic systems of impacting local weather are resolved accordin g to the echo analyses. Severe weathers are distinguished with [JP2]echo charact ers, future development trends of echo are understood by echo evolutions. For identified severe weathers with radar echos, signature recognitions and discerning means are built by the researches and the statistics of radar echoes. The main nowcasting method is the extrapolation, but the forcast experience is most important. The conclusion of the nowcasting is drawn by the forecasters bas ed on their forecast experiences. Nowcasting technological processes needs to be formulated for better nowcasting and severe weather warning.