Assimilation of radar reflectivity for rainfall nowcasting

Yann Lepoittevin (1) , Isabelle Herlin (1)

1 Clime - Coupling environmental data and simulation models for software integration

The paper describes an operational method of rainfall now-casting based on ground radar acquisitions with high space and time resolution. The nowcast horizon is between 30 minutes and 1 hour as required by prevention measures of flash floods. The characteristics of the input data justify the design of an image-based method that estimates wind fields from image acquisitions and forecasts the location and quantity of rain in the near future. The estimation phase relies on an iterative data assimilation of the radar acquisitions with an evolution model of motion and image fields, while the forecast is obtained by simulating these fields at the chosen horizon. The research is done in the context of a collaboration with the french company Numtech and the data are obtained with radars of the company Weather Measures.

Mots clés: Radar image; rain nowcasting; motion estimation; data assimilation

Domaines: Modélisation et simulation

Yann Lepoittevin, Isabelle Herlin. Assimilation of radar reflectivity for rainfall nowcasting. IGARSS - IEEE International Geoscience and Remote Sensing Symposium, Jul 2015, Milan, Italy. pp.933-936, ⟨10.1109/IGARSS.2015.7325919⟩. ⟨hal-01174046⟩