Improved forecasts of extreme weather events by future space borne Doppler wind lidar

Introduction An important goal in operational weather forecasting is to reduce the number of forecast failures, in particular those with large socio economic impact. Forecast failures of high-impact weather are often due to lack of observations over data sparse areas, such as the southern hemisphere, Tropics and Northern hemisphere oceans, over a prolonged period prior to the extreme event. International programmes such as the observing system research and predictability experiment (ThORPEx1)) show a growing interest in defining an observational network focussing on increased accuracy of high-impact weather forecasts. This network definition addresses fundamental questions related to observation strategies such as the relative merit of new polar orbiting satellites, giving a uniform global coverage of observations, versus e.g. targeting strategies where additional observations are constrained to pre-determined meteorologically sensitive areas. To answer these questions simulation experiments with state-of-the-art numerical weather prediction (NWP) models have proved great value to test future meteorological observing systems a priori on their ability to improve meteorological analyses and subsequently reduce the probability of forecast failures, which would make them a cost-effective investment.