A frost alert has been issued today for grape growers by the Weather Watch Centre. 

Head Weather Analyst Philip Duncan says Wednesday’s Antarctic blast is to blame.  “That bitterly cold air was blown up across the South Island on Wednesday and it’s another 24 to 48 hours until warmer northerlies blow it out into the Pacific.  Until then we have two nights where frosts are possible, especially inland”.

Mr Duncan says Central Otago, Marlborough and Wairarapa in the north are all vulnerable.

He says frosts should be relatively light and confined mostly to the ground but with temperatures dipping as low as minus 2 or 3 in some valleys frost protection measures may be needed early on Saturday and Sunday mornings to protect grapes.