To augment the routine observational network for better forecasts of high-impact weather events, targeting observations (TOs) have developed rapidly during the past several decades worldwidely. In special, tropical cyclone (TC) forecasts have benefitted a lot from these field campaigns. In this talk, research work and field campaigns of TOs are briefly overviewed. Then a method named the conditional nonlinear optimal perturbation (CNOP), which is utilized to identify the areas deserving additionally observed with priority in TOs, is introduced. Using some examples, we explain how to numerically use the CNOP method and demonstrate its impacts on TC forecasts and its latest application in real time operational forecasts. We hope the information will be useful and inspiring for the listeners.

CNOP,target observation,tropical cyclone