Where did you get the existence of sub-km (horizontal) grid forecasts from? Thus page https://www.dwd.de/EN/research/weatherforecasting/num_modell... contains the following sentence:
"The operational NWP models of DWD currently employ horizontal grid mesh widths between 2.8 and 13 km."
The convective cell tracking for nowcasting seems finer, IMO reasonable as it's about predicting watersheds down to <10km² area flash-flooding and causing the local creek to swell to actually dangerous levels/requiring partial evacuation of a valley.
The convective cell tracking for nowcasting seems finer, IMO reasonable as it's about predicting watersheds down to <10km² area flash-flooding and causing the local creek to swell to actually dangerous levels/requiring partial evacuation of a valley.