The intense storm that battered the capital and the South Island this week has certainly left a trail of destruction and disruption across a wide swathe of the country. In a simple sense, a very deep low - for the time of year - passed just south of the country with an active front that extended further. There was also a big high parked northeast of the country, so a very large pressure gradient developed between the two features. Over the distance of around 2800km the pressu