The storm that hit Northland and Auckland has been described by Metservice’s Bob McDavitt as an ‘eggbeater’ phenomenon. This is caused by low pressure colliding with high pressure.

Two lows moved down the country close together . They squeezed against the high, blocking the lows’ movement. The resulting pressure gradient caused high winds. The unstable moist air mass of the lows released heavy rain on contact with the high.

The New Zealand Herald. 12.07. 07

Just like March- but worse

Kaitaia centimetres from calamity

Rainfall in Kaeo 272.5 mm (24 hours)

The Northland Age, July 12 2007

Northern News July 25, 2007 Storm costs: $ 49 million