That blast brought scatterings of snows to Auckland and gave the city its coldest daily high, and caused chaos for the rest of the country.
The next icy blast should move in over the South Island at the end of Thursday and travel up over the North Island on Friday, Mr Duncan said.
"But there's not very much moisture in this system, so while it will be cold it's not going to be like the snow event we saw earlier this month - so that's the good news."
Snow was most likely to fall around Southland and Otago, but the heaviest falls would be around Canterbury, although the snow might not settle.
MetService forecaster Sarah Garlick said snow was also expected in Wellington on Rimutaka Hill, which was closed during the last cold blast when about 100 motorists became trapped in their cars.
"But [the snow] will be nowhere near as cold as that last event," Ms Garlick said.
Snow was also expected to fall on the Desert Rd, but the rest of the North Island should be unaffected by the blast.
Mr Duncan said the high, which was dredging up the cold air from the Antarctic, was 30 per cent smaller than the one which brought the earlier heavy snow fall.
"So it won't be as bitterly cold."
The blast should have cleared by the weekend, bringing clear days, but frosty nights.
"It won't last long and should be short-lived ... the weather should have improved for most areas by Saturday."
He warned farmers with young lambs to be prepared for the coldsnap.
