New diagnostic ideas

Combine surge and total sea level in maps

1. contour surge on top of total water level
2. contour surges relative to (modelled) Highest Astronomical Tide (or similar, e.g. Turner et al. 2010)

Plot Alert curves on ensemble plots

Plot Alert curves on ensemble plots, which capture the time varying tide following Flowerdew et al. 2010 E.g.:

E.g.