Abstract: In the paper, the strong convective weather happened in the mid and north part of Hohhot on August 4th, 2013 （one typical day of the flood season） was analyzed by live observation data collected by the conventional meteorology ways. The target of analysis the live data collected before the extreme weather happened was forecast the convective weather that may happen from noon to the evening. By analysis the thermal power between the high and low layer and stream distribution using the 08：00 data from air, T-logP and V-30,the results showed that the possibility of strong convective weather happened was extremely high. The successful forecast gave us a great guidance for next strong convective weather.