Blue Skies Weather & Climate Services has forecasted a snow event for Canterbury, starting from Tuesday next week.

The complex low-pressure system will move over New Zealand on Monday and Tuesday, lying east of the South Island for the rest of the week. This will bring a very cold southerly airflow over Canterbury, with snow expected for a few days.

Farmers, particularly those with lambs, should prepare for adverse conditions. Rain is anticipated on Monday, with heavier falls inland and cold temperatures.

Snow will initially be confined to areas south of Tekapo, with heavier falls above 400m in that region and further south in Otago.

On Tuesday, colder air will bring rain initially, transitioning to snow by the afternoon. Snow levels are expected to lower to 500m during the afternoon and further to 200m by the evening, with accumulations ranging from 10-20cm above 500m, 5-10cm above 300m, and a few centimetres above 200m.

Wednesday will remain overcast and very cold, with blustery southerly quarter winds. Snow will ease to flurries with increasing dry periods. Sleet showers are expected below 200m, with additional light accumulations above 200m.

From Thursday to Saturday, very cold temperatures will persist. Inland areas will mostly experience fine weather with sunny periods, while coastal areas and Banks Peninsula will see more cloud cover and isolated light snow flurries above 200m.

Travellers should be aware that passes in the Mackenzie Country may be impacted by heavy snow above 400m on Monday, along with roads in Otago.

Most passes are expected to be affected by snow on Tuesday, with potential impacts on higher roads on the western Plains, hill country, and Banks Peninsula on Tuesday night.

From Wednesday, only roads on Banks Peninsula are likely to be affected, though sleety showers may continue through early Saturday.