improver.cli.nowcast_optical_flow_from_winds module
Script to calculate optical flow components as perturbations from model steering flow
- process(steering_flow, orographic_enhancement, *cubes)[source]
Calculate optical flow components as perturbations from the model steering flow. Advects the older of the two input radar observations to the validity time of the newer observation, then calculates the velocity required to adjust this forecast to match the observation. Sums the steering flow and perturbation values to give advection components for extrapolation nowcasting.
- Parameters:
steering_flow (iris.cube.CubeList) – Model steering flow as u- and v- wind components. These must have names: “grid_eastward_wind” and “grid_northward_wind”.
orographic_enhancement (iris.cube.Cube) – Cube containing the orographic enhancement fields.
cubes (tuple of iris.cube.Cube) – Two radar precipitation observation cubes.
- Returns:
List of u- and v- advection velocities
- Return type: