Our last three-monthly predictions, and what actually happened.

What we predicted, July to September 2010          What actually happened, July to September 2010

What we predicted for July to September 2010

River flows are likely to be normal or below normal in the north and east of the North Island, normal or above normal in the western South Island, and near normal in other regions.

What actually happened during July to September 2010

River flows were above normal for most of the country, with some normal river flows in the northern part of both islands, and a small area of below normal river flow in Southland.

Interpreting these maps

Percentage chance of:

Mapped quantities for the past month, and the past three months, are based on the position of those flows in a distribution of historical flows from each flow recorder for that month or that season. (A season is any contiguous three-month period). At present the data used to estimate the distribution are flow data from the beginning of each flow record up to the year 2000. If a catchment is mapped as ‘normal’ this means that the flows for the period were in the middle tercile (third) of the historic distribution. Catchments mapped as ‘far below’ or ‘far above’ normal mean that their flows for the period correspond to the bottom or top 10% of the historic distribution. Catchments mapped as ‘below’ or ‘above’ normal had their flows respectively in the bottom or top tercile but not in the most extreme 10% of historic flows.