Storm.plot_ensembles

Storm.plot_ensembles(forecast=None, fhr=None, interpolate=True, domain='dynamic', ax=None, cartopy_proj=None, save_path=None, **kwargs)[source]

Creates a plot of individual GEFS ensemble tracks.

Parameters

  • forecast (datetime.datetime, optional) – Datetime object representing the GEFS run initialization. If None (default), fetches the latest run.

  • fhr (int, optional) – Forecast hour to plot. If None (default), a cumulative plot of all forecast hours will be produced. If an integer, a single plot will be produced.

  • interpolate (bool, optional) – If True, and fhr is None, track density data will be interpolated to hourly. Default is True (1-hourly track density data). False plots density using 6-hourly track data.

  • domain (str) – Domain for the plot. Default is “dynamic”. Please refer to Map Domain Options for available domain options.

  • ax (axes) – Instance of axes to plot on. If none, one will be generated. Default is none.

  • cartopy_proj (ccrs) – Instance of a cartopy projection to use. If none, one will be generated. Default is none.

  • save_path (str) – Relative or full path of directory to save the image in. If none, image will not be saved.

Other Parameters

  • prop_members (dict) – Customization properties of GEFS ensemble member track lines. Scroll down below for available options.

  • prop_mean (dict) – Customization properties of GEFS ensemble mean track. Scroll down below for available options.

  • prop_gfs (dict) – Customization properties of GFS forecast track. Scroll down below for available options.

  • prop_btk (dict) – Customization properties of Best Track line. Scroll down below for available options.

  • prop_ellipse (dict) – Customization properties of GEFS ensemble ellipse. Scroll down below for available options.

  • prop_density (dict) – Customization properties of GEFS ensemble track density. Scroll down below for available options.

  • map_prop (dict) – Customization properties of Cartopy map. Please refer to Map prop for available options.

Returns

ax – Instance of axes containing the plot is returned.

Notes

Note

The total number of GEFS members available for analysis is as follows:

  • 2020 - present - 31 members

  • 2006 - 2019 - 21 members

  • 2005 & back - 5 members

As the density plot and ensemble ellipse require a minimum of 10 ensemble members, they will not be generated for storms from 2005 and earlier.

Additionally, ellipses are not generated if using the default fhr=None, meaning a cumulative track density plot is generated instead.

The ensemble ellipse used in this function follows the methodology of Hamill et al. (2011), denoting the spread in ensemble member cyclone positions. The size of the ellipse is calculated to contain 90% of ensemble members at any given time. This ellipse can be used to determine the primary type of ensemble variability:

  • Along-track variability - if the major axis of the ellipse is parallel to the ensemble mean motion vector.

  • Across-track variability - if the major axis of the ellipse is normal to the ensemble mean motion vector.

The following properties are available for customizing ensemble member tracks, via prop_members.

Property

Description

plot

Boolean to determine whether to plot ensemble member tracks. Default is True.

linewidth

Forecast track linewidth. Default is 0.2.

linecolor

Forecast track line color. Default is black.

color_var

Variable name to color ensemble members by (‘vmax’ or ‘mslp’). Default is None.

cmap

If color_var is specified, matplotlib colormap to color the variable by.

levels

If color_var is specified, list of contour levels to color the variable by.

The following properties are available for customizing ensemble mean track, via prop_mean.

Property

Description

plot

Boolean to determine whether to plot ensemble mean forecast track. Default is True.

linewidth

Forecast track linewidth. Default is 3.0.

linecolor

Forecast track line color. Default is black.

The following properties are available for customizing GFS forecast track, via prop_gfs.

Property

Description

plot

Boolean to determine whether to plot GFS forecast track. Default is True.

linewidth

Forecast track linewidth. Default is 3.0.

linecolor

Forecast track line color. Default is red.

The following properties are available for customizing Best Track line, via prop_btk.

Property

Description

plot

Boolean to determine whether to plot Best Track line. Default is True.

linewidth

Best Track linewidth. Default is 2.5.

linecolor

Best Track line color. Default is blue.

The following properties are available for customizing the ensemble ellipse plot, via prop_ellipse.

Property

Description

plot

Boolean to determine whether to plot ensemble member ellipse. Default is True.

linewidth

Ellipse linewidth. Default is 3.0.

linecolor

Ellipse line color. Default is blue.

The following properties are available for customizing ensemble member track density, via prop_density.

Property

Description

plot

Boolean to determine whether to plot ensemble member track density. Default is True.

radius

Radius (in km) for which to calculate track density. Default is 200 km.

cmap

Matplotlib colormap for track density plot. Default is “plasma_r”.

levels

List of levels for contour filling track density.