"Fingers crossed it won't eventuate but it's better to be mentally prepared and start looking at options that if it does happen than putting our head in the sand.
"I think if it hits us it'll start with Otago like it usually does, and move up ... so potentially it might be a fizzer but we're just hoping people use common sense," Mr Grace said.
MetService meteorologist Rob Kerr said the gusty northwest gales were expected to batter parts of the South Island today but should ease overnight.
He said the strongest winds should be seen in Canterbury - with damaging gusts of 150km/h or more possible in the high country and foothills.
It was starting to kick off in Southland and Otago this morning, he said.
"It's going to be a dry northwest so that's what we talk about in the warnings as well, the elevated fire risk.
"These are strong winds so anybody out and about, particularly driving, it's going to be hazardous. We've seen in the past trees can be damaged, power lines can be damaged.
"In the last event there was trampolines flying around in Christchurch ... so even those urban areas are going to be affected today," Mr Kerr said.
Rain is also expected to plague the South Island, with a heavy rain warning in place for Fiordland, Westland and the headwaters of Otago and Canterbury rivers and lakes. It was expected to ease overnight or early Thursday.
The North Island would miss the wild weather due to a "persistent ridge" hovering over the top of the country, he said.
Auckland was expected to be relatively settled with cloudy periods and a bit of wind picking up later today.
Otago on high alert
Firefighters are on edge and taking all precautions as a "spike day" hits Otago today.
It comes a fortnight after two massive rural fires destroyed buildings and trees and led to evacuations at Saddle Hill and near Dunback.
The Otago Rural Fire Authority urged residents to be wary of fires because of the difficulty of containing them in today's weather conditions.
"We are always nervous with these sort of conditions," Otago Rural Fire Authority deputy principal rural fire officer Graeme Still said.
Resources and firefighters were prepared for any fires which might break out, he said.
The authority imposed a restricted season in the Lakes, Central, Coastal and Clutha fire zones during the weekend, meaning all open fires in the area - which covered from Duntroon in the north to Kaka Point in the south and east to Queenstown, Wanaka and Omarama - could only be lit with a permit. Only the Catlins fire zone remained in an open fire season.A Fire Service spokesman said firefighters from Outram attended two unpermitted rural fires on Monday night. Both were extinguished.
The weather woes could also extend to waterways, with heavy rainfall in the eastern South Island expected to affect rivers in Otago and Southland.
"We could see rivers rising rapidly ... when the front comes through late on Wednesday," he said.
The National Institute of Water and Atmospheric Research is predicting one of the driest summers on record as El Nino grips the country, which could present further headaches for firefighters.
Mr Still said the authority would also be exercising caution over the affected areas near Dunback and at Saddle Hill.
"We are aware of it, so we have got measures in place," he said.
"Anything that's been lit or has been on fire, there's potential if it hasn't completely extinguished for something to happen."
Both fires raged over more than 100ha and firefighters remained on the scene of the Dunback blaze through to last week mopping up the blaze.
"We have gone over the fire ground [in Dunback], put the cameras over it ... and we have had nothing showing for about six or seven days," he said.
"But you just don't know until you get a lot of rain. It's a bit of never say never until you have a lot of rain."
Firefighters were also being cautious with Saddle Hill.
"I'm pretty confident that there isn't anything at Saddle Hill," he said.
"I don't think there's anything to fear, but again it only takes something that's the size of a thumbnail."
Main centres forecast:
• Whangarei: Fine spells with the odd shower today. High 19C, low 11C. Tomorrow, cloudy periods and a fresh northwest. High 21C, low 13C.
• Auckland: Today will see fine spells with morning showers. High 17C, low 13C. Cloudy periods on Thursday. High 19C, low 14C.
• Hamilton: Cloudy periods today with a chance of evening shower. High 17C, low 11C. Tomorrow will see cloudy periods and showers. High 18C, low 13C.
• Tauranga: Morning and evening cloud today, otherwise fine. High 18C, low 12C. Cloudy periods continue tomorrow. High 19C, low 14C.
• Wellington: Fine spells with northerlies gusting 100km/h today. High 16C, low 10C. More wind tomorrow with briefly heavy rain and then showers. High 15C, low 10C.
• Christchurch: Fine and then cloudy today with strong northwesterlies gusting above 110km/h. High 23C, low 8C. Tomorrow, a period of morning rain and then fine. High 15C, low 4C.
• Dunedin: Today will see cloud increasing and evening rain with winds up to 100km/h. High 23C, low 7C. Showers clearing on Thursday and southwest winds dying out. High 14C, low 6C.
- Additional reporting: Otago Daily Times
