Fluctuating winds from intense thunderstorm/downburst are often modelled as the amplitude modulated evolutionary stochastic processes and simulated based on the spectral representation method. Aspects of the modelling and simulation include assessing time and frequency dependent power spectrum, and the identification of the amplitude and frequency modulations are not straightforward. The present study uses the S-transform and discrete orthonormal S-transform to evaluate the time-frequency power spectral density (TFPSD) functions and coherence functions of nonstationary winds. The results for a thunderstorm/downburst event indicate that the coherence is time-dependent. The use of the TFPSD functions and a newly developed simulation method to generate winds acted on single and multiple points with a time-dependent coherence is shown. A comparison of the mean of the TFPSD of the simulated winds to its corresponding target is used to validate the adequacy of the simulation models. The use of the simulated records to assess the record-to-record variability on the maximum responses of a nonlinear inelastic single-degree-of-freedom system is given.

来自强雷暴/暴发的波动风通常被建模为调幅的演化随机过程，并基于频谱表示方法进行模拟。建模和仿真的各个方面包括评估与时间和频率有关的功率谱，并且振幅和频率调制的识别并不简单。本研究使用S变换和离散正交S变换来评估非平稳风的时频功率谱密度（TFPSD）函数和相干函数。雷暴/暴发事件的结果表明，相干性与时间有关。显示了使用TFPSD函数和新开发的模拟方法来生成作用于具有时间相关性的单点和多点的风的方法。将模拟风的TFPSD的平均值与其对应目标进行比较，以验证模拟模型的适当性。给出了使用模拟记录评估非线性非弹性单自由度系统最大响应的记录间差异。