It is a crucial issue to make an intense plasma channel in the atmosphere for laser triggered lightning. The laser characteristics of laser propagation and plasma generation have been studied under various weather conditions. The line density of plasma channel in snowy weather is less than that in fine weather due to the laser energy attenuation and the decrease of aerosols, the cores of plasma beads, by snow. To initiate a leader at the top of lightning tower, the line density of plasma channel is needed to be over one hundred per meter. Some remedies to overcome this effects will be discussed.
