pysteps.nowcasts.extrapolation.forecast(precip, velocity, timesteps, extrap_method='semilagrangian', extrap_kwargs=None, measure_time=False)#

Generate a nowcast by applying a simple advection-based extrapolation to the given precipitation field.

  • precip (array-like) – Two-dimensional array of shape (m,n) containing the input precipitation field.

  • velocity (array-like) – Array of shape (2,m,n) containing the x- and y-components of the advection field. The velocities are assumed to represent one time step between the inputs.

  • timesteps (int or list of floats) – Number of time steps to forecast or a list of time steps for which the forecasts are computed (relative to the input time step). The elements of the list are required to be in ascending order.

  • extrap_method (str, optional) – Name of the extrapolation method to use. See the documentation of pysteps.extrapolation.interface.

  • extrap_kwargs (dict, optional) – Optional dictionary that is expanded into keyword arguments for the extrapolation method.

  • measure_time (bool, optional) – If True, measure, print, and return the computation time.


out – Three-dimensional array of shape (num_timesteps, m, n) containing a time series of nowcast precipitation fields. The time series starts from t0 + timestep, where timestep is taken from the advection field velocity. If measure_time is True, the return value is a two-element tuple containing this array and the computation time (seconds).

Return type