Severe storm warning issued

Herald online

3 Oct, 2011 12:00 AM3 mins to read

A 'very active front' carrying showers and thunderstorms Is expected to cross the upper North Island afternoon. File photo / Thinkstock

Do you have amazing weather photos or video? We'd love to see them!
Email us

A severe storm front could bring damaging tornadoes to the upper North Island this afternoon, forecasters warn.

Metservice said a "very active front" carrying showers and thunderstorms was expected to cross Auckland, Northland and Waikato from early afternoon.

WeatherWatch.co.nz said there was an explosive band of thunderstorms just west of Auckland, but the thunderstorms were remaining offshore so far.

WeatherWatch said there had been 19,000 lightning strikes detected so far today, with 1900 in the last hour alone, but that about 90 to 95 oer cent of the thunder activity is offshore in the eastern Tasman Sea.

Earlier in the day, Metservice said some of the thunderstorms carried by the system could be severe, causing wind gusts of 110km/hr and carrying the risk of damaging tornadoes, it said.

"These squally winds and possible small tornadoes may cause some structural damage, including damage to trees and power lines, and make driving hazardous."

It advised anyone caught in the threatening weather to take shelter immediately.

The advisory comes as MetService forecasts "big contrasts" between the weather over north and south of the country.

Met Service spokesman Daniel Corbett said the north of New Zealand is expected to be in a warm, moist northerly flow for the next few days.

"There will be showery episodes during this time with heavy falls in some places, particularly today, when thunderstorms are part of the mix as well. Daytime temperatures should be in the late teens to early twenties."

On the other hand, the south of the South Island is expected to be reasonably cool and dry over the next few days, with little or no rain expected and daytime temperatures generally around the mid teens.

"In the in-between regions, from about the central North Island through to Canterbury, wet conditions are likely to continue on and off for the next few days, but with a gradual and significant cooling taking place. Heavy rain in parts of Bay of Plenty, the central North Island high country, Taranaki, Nelson and Marlborough should ease on Tuesday. On Tuesday, snow is likely down to about 500 metres in north Canterbury and Marlborough, and possibly around Nelson Lakes."

The wet - and gradually colder - conditions over parts of Canterbury and Marlborough over the next few days are likely to place stress on young livestock. Heavy rain or showers could also pose a hazard to motorists.