Abstract: In this article, we provide a short review on the applications of ensemble sensitivity analysis (ESA) to high-impact weather events in mid-latitude of Northern Hemisphere. As an efficient and computationally inexpensive method, ESA has been applied to diagnose the forecast uncertainties in the extratropical cyclones, typhoons/hurricanes and their extratropical transitions, convective processes, etc. This method is very flexible: one can adjust its forecast metrics and/or state vectors based on the practical needs. ESA was applied in three different ways to diagnose the uncertainty in predicting a high-impact winter storm in December 2010 based on the choice of forecast metrics: sensitivity using the EOF approach, sensitivity using run cycle difference, and forward sensitivity regression using short-range forecast errors. All these three approaches confirmed that the track’s uncertainty for this cyclone was linked to the initial uncertainty in the short-wave trough over the southern Great Plains based on the 50-member ECMWF ensemble. Moreover, the cyclone intensity uncertainty was associated with the trough and ridge systems embedded in a Rossby wave train over the Northeast Pacific and the central U.S. Therefore, the ESA method is very robust for midlatitude cyclones in analyzing their forecast uncertainty, determining initial-condition sensitive regions, and diagnosing the mechanism for the error growth.