14.5. Smooth Contour

The attribute is best used to smooth contours when contouring a sparse grid (e.g., when your data has a large grid spacing). This will use a spline interpolation.

MetPy smooth_contour Documentation

Here is an example (Fig. 14.2) of using smooth_contour, notice how the black contours, which have had no smoothing applied, have clear vertex points (e.g., angles) to the contours whereas the red contours, which have been refitted with a zoom factor of four, are much smoother.

Fig. 14.2 This map shows 500-hPa heights in solid black contours and smoothed contours using the smooth_contour attribute in red using a zoom factor of 4.