Weather: 'Severe rain' to hammer New Zealand as Cyclone Oma comes close

Kiwis, prepare to get wet this weekend as heavy falls are forecast to bear down on the country with a cool southerly gale.

While Cyclone Oma is not expected to directly threat New Zealand over the next few days, moisture from that storm - as well as another weather system whipping its way up the country - will bring a mixture of intense showers and drizzle, according to WeatherWatch.

It has prompted MetService to issue a severe weather watch on Friday and Saturday for upper parts of the North Island.

"Warm tropical air is expected to bring rain with potentially heavy falls to Northland and north Auckland," said meteorologist Rob Kerr.

"The current Severe weather watch also covers a slow-moving front affecting south-western parts of the South Island, with heavy rain possible until the early hours of Friday morning."

But other parts of the country aren't out of the woods either, with rain expected from Taranaki down to Kapiti, and scattered showers over eastern parts of the South Island.

The intensity of that rain may be mixed, however, with WeatherWatch suggesting Waikato will only receive a small amount of rain.

Sunday and Monday will see the heaviest rain when the "unpredictable" weather system coming from the south is expected to be directly over the North Island.

NIWA forecaster Ben Noll told Magic Talk's Peter Williams it was possible the system could bring flooding and destruction similar to that which Cyclone Gita delivered last year.

"The reason that could occur is because the soil right now is very dry, and that means it is kinda like concrete, so when the rain falls on that soil, that may just run off and not get absorbed by the ground," Mr Noll said on Tuesday.

Temperatures are also likely to fall, with some parts of Southland, Otago and Canterbury falling 20degC from recent highs.

Newshub.