Dry March may herald mild autumn

March was a near-record dry period for the south and experts predict above-average temperatures will continue in the region throughout autumn.

45S Weather Services figures show Invercargill rainfall totalled 32.2 millimetres for March, only 34.6 per cent of the normal rainfall but short of the 22.2mm low recorded in March 1947.

Last month was the third-warmest March on record, with afternoon highs exceeding 20 degrees Celsius on all but two days from March 22 to March 31.

The highest temperature in Invercargill last month was 26C, on March 30.

The warmth is expected to continue across the lower South Island throughout autumn, as the National Institute of Water and Atmospheric Research (Niwa) forecasts neutral offshore weather patterns will bring above-average temperatures.

Niwa principal scientist Dr Andrew Tait said milder autumn temperatures were likely to remain in the region during the next three months, although there would not be a return to summer highs.

The extremely dry weather experienced in late summer and early autumn, caused by persistent anticyclone and high pressure systems, was not expected to dominate during the next three months, he said.

"We're breaking out of that period and we're getting back into the normal type of weather patterns.

"It's kind of like a mixed bag."

However, the dry summer meant soil moisture levels and river flows were low, so above-average rainfall would be needed to replenish reserves, he said.

Southland, Clutha and Central Otago areas could expect near-normal or above-normal rainfall during the next three months.

Historically, rainfall from April till June is between 283mm and 339mm in Invercargill, 208mm to 258mm in Gore, 217mm to 254mm in Queenstown, and 1413mm to 1892mm in Milford Sound.

The Southland Times