More polar blasts to come: weather expert

Forecasters expect turbulent northwesterlies to dominate central New Zealand until mid-week. Photo / Dean Purcell

Cold weather this month has caused soaring electricity demand compared with the same time last year.

Lines company Vector said during a "cold snap" in July its peak load was up 74 MW on the same week the year before.

The company said that amount was equivalent to the maximum demand for 24,666 households.

WeatherWatch said polar blasts were expected to hit next month too."August can be a surprisingly nasty month sometimes.

But with every week that now passes we are getting more sunlight and spring-conditions are showing more and more hints of arriving and setting in," head weather analyst Philip Duncan said today.

Dismal weather is expected to douse parts of the country today.

Forecasters expect turbulent northwesterlies to dominate central New Zealand until mid-week.

"Western areas are likely to be peppered by showers, while the east should remain mostly dry with temperatures reaching the late teens in some spots," MetService said.

Severe weather watches were in place for three regions today.

In the eastern Bay of Plenty, MetService expected 70-90mm of rain to fall within 12 to 15 hours.

In Fiordland and Westland south of Otira, up to 70mm could fall within 12 hours.

In parts of Westland north of Otira, rainfall could exceed 80mm today.

A strong wind advisory was in place for boaties in Auckland, where gusts were expected from Bream Head to Cape Colville, and winds were expected to pick up this morning and afternoon.

Meanwhile, a front over the Tasman Sea was expected to move east, crossing western parts of the South Island late today.

MetService said a moist northerly flow would precede the front, brining more heavy rain to western parts of the South Island.

Forecasters said a separate front was expected to dump heavy rain on the eastern Bay of Plenty later today and early tomorrow.

MetService said the latter part of the working week would be unsettled for many parts of the country. Snow was expected for some mountainous areas later this week.