The numerical weather prediction system at the Italian Air Force Weather Service impact of non-conventional observations and increased resolution

The impact of non-conventional observations and increased horizontal resolution on the numerical weather prediction (NWP) system of the National Center for Aeronautic Meteorology and Climatology of the Italian Air Force (CNMCA) has been investigated. The present study is part of ongoing research activities whose goal is the improvement of CNMCA's operational numerical weather prediction capabilities through the assimilation of non-conventional observations. Additional data derived from satellite observations, such as 10 m wind retrieved from Quikscat polar-orbit satellite, atmospheric motion vectors (AMVs) from Meteosat geostationary satellites and manual and automated aircraft observations were used. The NWP system, which is in operational use, is based on an "observation space" version of the 3D-Var method for the objective analysis component (3D-PSAS), while the prognostic component is based on the High Resolution Regional Model (HRM) of the German Meteorological Service (DWD). The analysis and forecast fields derived from the NWP system were objectively evaluated through comparisons with radiosonde and conventional surface observations. Comparisons with parallel runs of the HRM model starting from the 3D-Var operational analysis have showed that each of those observations have a measurable positive impact on forecast skill.