The Europe Swiss HD 4x4 Nowcast is recalculated every hour to improve the short-term prognosis.
For this purpose, in-situ measurement data (e.g. 2m temperature) and radar data are included to improve the model’s initializing fields reflecting the current weather state at model start.
This data assimilation causes major differences from model run to model run, especially in shower/thunderstorm conditions.
Improvements can also be seen in situations with an existing temperature inversion or with changes in e.g., cloud cover that are either captured too late, or even not at all, by other models.
The current status of the model system is on average doing better than the one without data assimilation. More components and further developments are planned.