Outlook: settled rainfall after April deluge

After a rain-drenched April, forecasters are expecting a return to normal rainfall levels over the next three months. Photo / File

After a rain-drenched April, what falls over the country between now and July is expected to be closer to normal.

That's according to the latest climate outlook issued by the Niwa, showing that rainfall totals are most likely to be near normal - a 40 to 45 per cent chance - in the north of the North Island and east of the South Island.

Seasonal rainfall totals were about equally likely to be below normal (a 35 to 40 per cent chance) or near normal (40 per cent) for the west and east of the North Island and the north and west of the South Island, the institute reported.

The more settled forecast would be a welcome change for centres like Te Puke, Taupo and Warkworth that, by the middle of this month, had already recorded their wettest April ever after a triple-hit of storms fuelled by moisture funnelled down from the tropics.

Some regions could also see warmer temperatures.

Over the next three months, temperatures were meanwhile equally likely to be above or near average for the north and west of the North Island and the north of the South Island, and most likely to be near average elsewhere.

"As we transition towards winter, frosts and cold snaps will occur from time to time in cooler locations, even in regions where elevated chance for higher than normal seasonal temperatures is forecast," Niwa reported.

"In fact, the first half of May is expected to experience cold outbreaks, with below or well below normal temperatures for the time of year - this will be in stark contrast to what was observed during April."

Source / NIWA

Soil moisture levels and river flows were about equally likely to be near or above normal or above normal in the north of the North Island and the east of the South Island.

In the west and east of the North Island, soil moisture levels and river flows were most likely to be in the near normal range.

Soil moisture levels and river flows are about equally likely to be near or below normal in the north of the South Island.

In the west of the South Island, soil moisture levels are about equally likely to be below normal or near normal, and river flows most likely to be in the below normal range.

In the big picture, forecasters expected a transition towards El Nino conditions over the next three months was slightly more likely than not.

Models indicated an increasing chance for El Nino becoming established later during the winter, with a nearly 70 per cent chance for the August to October period, although such forecasts tended to have lower accuracy at the start of winter compared with other times.