Metservice has issued a heavy snow watch, with snow possible down to 100 metres in Southland and southern Otago tomorrow, prompting a warning to motorists from the New Zealand Transport Agency.

Waka Kotahi NZ Transport Agency is encouraging those intending to travel to plan ahead and prepare for winter driving conditions.

Journey Manager Tresca Forrester said motorists should be prepared for icy conditions and snow.

"Our contractors will be working hard to keep roads open, applying grit and de-icing material, but people should keep a close eye on the conditions as some road closures are possible.”

Road snow warnings have been issued on the following highways overnight and into Thursday (July 23):

• Lindis Pass

• Lewis Pass

• Haast Pass

• Dunedin to Waitati Highway – Strong winds are already being experienced in this area.

• Crown Range Road

• Arthurs Pass

• Milford Road (closed overnight at 4pm Wednesday and likely to remain closed throughout Thursday). 

Ms Forrester also asks motorists to ensure their vehicles are safe, roadworthy and well equipped for winter driving. 

“We want everyone to keep safety in mind, so please plan ahead and allow extra time for your journeys and drive to the road and weather conditions. Maintain a greater following distance between your vehicle and the one in front, and to slow down and be prepared for unexpected hazards.”

Waka Kotahi’s website contains more easy tips for safe winter driving:

Winter driving tips

• Check weather and travel conditions on highways before you start your trip and on breaks throughout your journey - use www.journeys.nzta.govt.nz or call 0800 4 HIGHWAYS (0800 44 44 49).

• Ensure your car is safe and equipped: spare tyre, warrant of fitness up-to-date, lights, brakes and wind-wipers all working, clean windscreen inside and out, check tyre treads to ensure good grip.

• If you are travelling long distances, share the driving and have regular breaks.

• Wear your seat belt throughout the journey and check your passengers have theirs clicked in too.

• Driving on roads that are exposed to snow and ice can be treacherous, so slow down and drive to the conditions, not the allowable/legal speed limit. Increase the following distance between you and the vehicle ahead.

• Be prepared when travelling in case of delays on the road, particularly in alpine conditions. Make sure you have warm clothes/food/water/charged mobile phone. In an emergency, phone 111. Bear in mind some parts of the highway have no cell coverage.

• Learn about winter driving HERE, including how to get your vehicle ready and if you are driving in an area where chains may be needed, practise putting them on before you go so you are not caught out.