\label{fig:pwi_spatial_summary}
Composite mean 500 hPa circulation for days (with 30-day running mean applied) where the PWI was greater than its 90th percentile. Gray streamlines indicate the direction of the composite mean wind, while the black contours show the composite mean streamfunction zonal anomaly (dashed contours indicate negative values and the contour interval is $2.5 \times 10^6 \: m^2 s^{-1}$). 