With the improved model MM5, the impact of a height-dependent sounding balloon’s drifting on a mesoscale numerical model is analyzed, using new sounding data with accurate position information at each pressure level. Simulations of a gale and a temperature decrease indicate the following: the differences in the initial meteorological element fields, especially the velocity field, caused by position correction would be great in the lower layers, even exceeding that in the upper layers, when the atmospheric motion becomes strong below 500 hPa, although the differences are greater in the upper layers than in the lower layers in the mass. Position correction can reduce the simulation errors not only in the numerical values but also in the sphere of influence, so the results approach the observed data more closely. After position correction, the model can accurately simulate the southward movement of the strong wind and temperature decrease. The simulated foreland of the strong wind corresponds with the observed data, and the variation in the temperature field is quite consistent with the variation in the velocity field.