swirlspy.qpf package

Submodules

swirlspy.qpf.persistence module

swirlspy.qpf.persistence.persistence(xr2d, timesteps, timesteps_size)

Forecast by persistence, accepting an observation xarray and returning a forecast xarray. Persistence means that the forecast is exactly same as the observation. While it sounds trivial, this is usefulf for benchmarking the performance of another QPF algorithm.

Parameters

  • xr2d (xarray.DataArray (2-dimensional, in 'x' 'y')) – The xarray containing data to be forecast

  • timesteps (int) – Number of timesteps to be forecast

  • timesteps_size (int) – Time interval between each steps, in minutes.

Returns

persistence_xrnd – Data values in ‘xr2d’ being copied along the ‘end_time’ axis, coordinates of ‘end_time’ axis have a unique value for each timestep.

Return type

xarray.DataArray

swirlspy.qpf.rover module

swirlspy.qpf.sla module

swirlspy.qpf.sla.sla(qpf_xarray, motion_u, motion_v, steps=6)

Calculates forecast reflectivity using Semi-Lagrangian Advection from horizontal and vertical motion fields.

Parameters

  • qpf_xarray (xarray.DataArray) – Contains reflectivity data. First element of array corresponds to the geographic upper left corner.

  • motion_u (xarray.DataArray) – x component of motion field.

  • motion_v (xarray.DataArray) – y component of motion field.

Returns

forecast – A xarray.DataArray populated with forecast reflectivity and metadata.

Return type

xarray.DataArray