Outlook and outcome – January to March 2002

Rainfall was above average in Taranaki,Whanganui, and Buller as was predicted in the January to March Outlook. North and central Canterbury received more rain than was forecast. Parts of Waikato, Bay of Plenty, and East Cape were drier than expected.

Air temperatures were normal over much of the country as was expected, although large areas were cooler than forecast. It was warmer than expected in the west of the South Island.

River flows were above normal as forecast in Wellington and Buller, but lower than expected in west Otago and Southland. Eastern South Island flows were higher than expected.

The outcome maps shown here give the tercile rankings of the rainfall totals and mean temperatures that eventuated for these months. Terciles were obtained by dividing ranked January to March data from the past 30 years into three groups of equal frequency (lower, middle and upper one-third values) and assigning the data for the present year to the appropriate group. (Click to enlarge)

As an approximate guide, middle tercile rainfalls often range from 80 to 115% of the historical average. Middle tercile air temperatures typically occur in the range of the average plus or minus 0.5°C.