River flows update, July 2010
Monthly and seasonal river flow information, and our outlook for the coming three months.
June river flows reflected the fact that the month was a very wet one across much of the country, especially in the east of both islands.
Flows over the last three months (April to June 2010) ranged from above normal on the east coast and in the north, central, southwest and east of the South Island, to well below normal in parts of Northland and the Waiarapa.
Outlook by region, July to September 2010
|Northern North Island||Normal or below normal streamflows are likely|
|Southwest North Island||Normal streamflows are likely|
|Southeast North Island||Normal or below normal streamflows are likely|
|Northern South Island||Normal streamflows are likely|
|West and south South Island||Normal or above normal streamflows are likely|
|Eastern South Island||Normal streamflows are likely|
Maps and more details of our three-monthly outlook for river flows, soil moisture, rainfall, and temperature are available in NIWA's Seasonal Climate Outlook. See the latest New Zealand Climate Update for more general climate forecasts and restrospective information.
Note on mapped quantities
Mapped quantities for last month and the last three months are based on the position of those flows in a distribution of historical flows from each river flow recorder for that month or that 'season' (where 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.