South Canterbury will not escape Tropical Cyclone Lusi "completely unscathed", MetService says.
Meteorologist John Law said clouds over South Canterbury would build up from tomorrow, bringing heavy rain to the region on Sunday.
Lusi has ravaged Vanuatu, killing three people as it passed down the middle of the country, causing widespread destruction.
In a severe weather watch issued just after 10am yesterday, MetService added Bay of Plenty and northern Gisborne to the areas expected to get "significant heavy rain". Areas previously identified as likely to be hard hit were Northland, Auckland and the Coromandel Peninsula.
Mr Law said the weather situation for South Canterbury was "a tricky one".
MetService would have a better understanding of what was in store for the region by the second half of the weekend, he said. "There's still a little bit of uncertainty on how it pans out."
He said daytime temperatures at the weekend would fluctuate between 19 and 21 degrees Celsius across the district, while the lows would be in the mid-teens.
"Overall, [South Canterbury] is not in a bad spot."
Meteorologists have warned that Lusi could threaten Christchurch, which is particularly vulnerable after heavy rain last week caused widespread flooding. The threat of flooding in the city is thought to have increased as a result of earthquake-induced ground deformations. Parched North Island farmers fear Lusi's rain may be too intense to provide much benefit.
Rain and easterly gales are expected to spread on to northern New Zealand from later on Friday, and southwards across the remainder of the North Island on Saturday, then to the upper and eastern South Island later on Saturday and Sunday.
- The Timaru Herald