Seasonal Climate Outlook: April - June 2006

Seasonal Climate Outlook: April - June 2006

A Mild Late Autumn, Soil Moisture To Continue Low In Canterbury And Otago

The next three months are likely to be mild overall, according to National Climate Centre predictions.

The NIWA National Climate Centre outlook for April – June predicts above normal temperatures for most regions. Below normal soil moisture levels are likely in coastal Canterbury and east Otago. The Centre says normal or below normal rainfall is likely in the catchments of the South Island hydro lakes.

Overall Picture

Temperature: Air temperatures are very likely to be above normal in the North Island and are likely to be above normal in most of the South Island. Sea surface temperatures around New Zealand are expected to be near or above normal through June.

Rainfall, Soil Moisture, and Stream flows: Rainfalls are likely to be normal or below normal in most of the South Island, and the southwest North Island, while normal or above normal rainfall is likely for the northern North Island. Normal or above normal soil moisture levels and streamflows are likely in the northern North Island, with normal conditions likely in the southeast of the North Island. Normal or below normal soil moisture levels and streamflows are likely in the northern South Island, while below normal conditions are likely elsewhere in the South Island and in the southwest of the North Island.

Regional predictions for the next three months:

Northland, Auckland, Waikato, Bay of Plenty: Above normal temperatures are very likely. Normal or above normal rainfall is likely, as are stream flows and soil moisture levels.

Central North Island, Taranaki, Wanganui, Manawatu and Wellington: Above normal temperatures are very likely. Normal or below normal rainfall is likely, with below normal soil moisture levels and stream flows.

Gisborne, Hawkes Bay, Wairarapa: Above normal temperatures are very likely. Normal rainfall, soil moisture levels and stream flows are likely.

Nelson, Marlborough, Buller: Above normal temperatures and normal rainfalls are likely. Normal or below normal soil moisture levels, and stream flows are likely.

West Coast, Alps and Foothills, Inland Otago, Southland: Above normal temperatures are likely. Normal or below normal rainfall is likely. Below normal or normal soil moisture and stream flows are likely.

Coastal Canterbury, East Otago: Normal or above normal temperatures and normal or below normal rainfalls are likely. Below normal stream flows and soil moisture levels are likely.

Background

Climate and Oceans: Late autumn is likely to see a tendency for weaker than normal westerlies over New Zealand.

The tropical Pacific is in a weak La Niña state, which usually means a tendency for weakened westerlies and more northerly wind flows, generally mild temperatures, and a tendency towards above normal rainfalls in the northeast and below normal falls in the southwest. The tropical Pacific should ease to neutral conditions by winter 2006.

For the remainder of the tropical cyclone season through the end of April, normal cyclone activity is still expected. For New Zealand, there is still a small risk of a cyclone affecting the country over the next month.

ENDS

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