Storm Composite Plots¶

Storm composite plots overlay three meteorological fields on a geographic map:

PWAT (Total Precipitable Water) as color-filled contours
MSLP (Mean Sea Level Pressure) as contour lines with labels
VIMF (Vertically Integrated Moisture Flux) as wind barbs or quiver arrows

These plots are useful for assessing cyclone and major storm development.

Single Timestep¶

from modverif.composite import plot_storm_composite_timestep

fig, ax = plot_storm_composite_timestep(
    'model.cfdb',
    time_index=0,
)

# Or save directly
plot_storm_composite_timestep(
    'model.cfdb',
    time_index=0,
    output_path='composite_t0.png',
)

Custom Variable Names¶

If your dataset uses different variable names:

plot_storm_composite_timestep(
    'model.cfdb',
    time_index=0,
    vimf_u_var='vimf_u',
    vimf_v_var='vimf_v',
    pwat_var='pwat',
    mslp_var='mslp',
)

Animated Sequence¶

Generate PNG frames for all timesteps plus an animated WebP:

from modverif.composite import plot_storm_composite

png_files, webp_path = plot_storm_composite(
    'model.cfdb',
    output_dir='composite_frames/',
)

Time Filtering¶

png_files, webp_path = plot_storm_composite(
    'model.cfdb',
    output_dir='composite_frames/',
    start_time='2023-02-12T06:00',
    end_time='2023-02-13T00:00',
)

Animation Options¶

png_files, webp_path = plot_storm_composite(
    'model.cfdb',
    output_dir='composite_frames/',
    webp_duration=500,   # ms per frame
    webp_quality=80,     # 1-100
    webp_loop=0,         # 0 = infinite
)

Side-by-Side Model Comparison¶

Compare two models (e.g., WRF vs ERA5) with synchronized timesteps:

from modverif.composite import plot_storm_composite_comparison

png_files, webp_path = plot_storm_composite_comparison(
    'wrf.cfdb',
    'era5.cfdb',
    output_dir='comparison_frames/',
    label_a='WRF',
    label_b='ERA5',
)

Only timesteps that exist in both datasets are plotted. The color scale is computed from both datasets for consistent comparison.

Single Comparison Timestep¶

from modverif.composite import plot_storm_composite_comparison_timestep

fig, (ax_a, ax_b) = plot_storm_composite_comparison_timestep(
    'wrf.cfdb',
    'era5.cfdb',
    time_index=0,           # index into matched timesteps
    label_a='WRF',
    label_b='ERA5',
)

The time_index refers to the index into the intersection of both datasets' time arrays, not either dataset's raw time array.

Different Variable Names Per Dataset¶

When datasets use different naming conventions:

png_files, webp_path = plot_storm_composite_comparison(
    'wrf.cfdb',
    'era5.cfdb',
    output_dir='comparison_frames/',
    label_a='WRF',
    label_b='ERA5',
    # WRF variable names
    vimf_u_var_a='vimf_u',
    vimf_v_var_a='vimf_v',
    pwat_var_a='pwat',
    mslp_var_a='mslp',
    # ERA5 variable names
    vimf_u_var_b='vimf_u',
    vimf_v_var_b='vimf_v',
    pwat_var_b='tcwv',
    mslp_var_b='sp',
)

Different Projections¶

Each panel automatically uses its own map projection based on the dataset's CRS. For example, a WRF dataset in Lambert Conformal and an ERA5 dataset in PlateCarree will each render correctly in their respective panels.

Plot Customization¶

All composite functions accept these keyword arguments:

Parameter	Default	Description
`vector_type`	`'barbs'`	`'barbs'` or `'quiver'` for VIMF display
`thin_factor`	auto	Stride for vector thinning (auto-computed from grid size)
`pwat_cmap`	`'YlGnBu'`	Colormap for PWAT fill
`pwat_levels`	auto	Contour levels for PWAT (auto-computed from data)
`mslp_levels`	960--1040 by 4	Contour levels for MSLP in hPa
`mslp_color`	`'black'`	Color for MSLP contour lines
`vector_color`	`'black'`	Color for barbs or quiver arrows
`figsize`	`(14, 10)`	Figure size (comparison default: `(24, 10)`)
`dpi`	150	Output resolution