The models for estimating storm surge in shallow water regions require as input a realistic atmospheric forcing in the typhoons. In this work, an improvement of the storm surge estimation is proposed by considering the distortion of the pressure distribution and the relevant wind field in land falling typhoons.
　The distribution of the pressure and wind in the real typhoon is investigated on the base of data for four typhoons, attacked Kyushu area-T9918, T9119, T9117 and T9307. The validity of Myers radial symmetric pressure distribution is examined. In the front zone of the typhoon, the observed pressure is lower than calculated by Myers formula. The obtained distortion from the radial symmetry of Myers distribution is parameterized as an analytical expression for the modified Myers pressure distribution is proposed. The modified Myers pressure distribution provided closer estimations to the observed ones in comparison with Myers pressure formula.
　The influence of the pressure distortion on the wind field in the typhoon is examined. The comparison between observed and calculated wind shows that the previous models underestimated wind, while utilizing modified Myers pressure and taking into account the vertical structure of typhoon by super gradient wind, leads to better agreement with observations.
　The response of the storm surge model to the corrected pressure and wind field is checked.Considerations of the pressure distortion and super gradient wind in the typhoon improve the storm surge estimation. More accurate diagnosis of the storm surge magnitude in coastal areas is achieved by the incorporation of the transformation of the typhoon structure due to land approaching and landfalling.