IMPROVER: The New Probabilistic Postprocessing System at the Met Office

Abstract The Met Office in the United Kingdom has developed a completely new probabilistic postprocessing system called IMPROVER to operate on outputs from its operational numerical weather prediction (NWP) forecasts and precipitation nowcasts. aim is improve forecast information public other stakeholders while better exploiting current future generations of underpinning kilometer-scale NWP ensembles. We wish provide seamless nowcasting medium range, consistency between gridded site-specific forecasts, be able verify every stage processing. software written modern modular framework that easy maintain, develop, share. allows provided with greater spatial temporal detail faster update frequency than previous postprocessing. Independent processing chains are constructed for each meteorological variable consisting series stages predefined grids blend several inputs give frequently updated, solution. Probabilistic produced as standard, option extracting most likely or yes–no outcome if required. Verification can performed at all stages, although it only currently switched significant when run real time. been producing real-time output since March 2021 became spring 2022.