Another round of stormy spring weather is moving in tomorrow and Thursday, bringing heavy rain and gales to parts of the country.

Engineers will today pack explosives into huge boulders that have closed Milford Rd in Fiordland, as residents face their fifth day cut off.

An independent weatherman has hit out at the MetService, claiming it was too slow to issue a severe weather warning for Auckland at the weekend.

Boulders weighing up to 200 tonnes have blocked access to Milford Sound as galeforce winds and driving rain sweep across the country.

Large areas of New Zealand are preparing for a storm cell "bigger and nastier" than the weather bomb that tore roofs from homes at Wanganui earlier this year.

Despite 120km/h gales in the South Island and lower North Island there have been no reports of damage, emergency services say.

Despite heavy rain beginning to ease around the Tasman region, flooding around Westport still has the town completely cut off. The rain is set to continue over the lower half of the North Island through Monday.