Z = np.exp(1j * np.pi * coords[:, :, (0)] / 180.0)
Z *= np.exp(0.25j * np.pi / 2.0)
X = np.arange(300)
Y = np.arange(450)
N = 2
levels = 90 * (0.5 + (np.arange(N) + 0.5) / N)
c1 = plt.contour(X, Y, abs(np.angle(Z) * 180 / np.pi), levels=levels)
c2 = plt.contour(X, Y, abs(np.angle(Z * np.exp(0.5j * np.pi)) * 180 / np.pi
    ), levels=levels)
Stop pyplot.contour from drawing a contour along a discontinuity