The week of July 14th to 21st is expected to be a week of continuous severe weather across New Zealand. What South East Australia has just expected, and is still expected to experience.. is also expected to move across the Tasman Sea and amplify before impacting New Zealand everyday for the next week. Above image 10 day snowfall via Windy.

 

A series of cold fronts, upper level troughs packing very cold air, and some intense low pressure systems are forecast to continuously move across the Tasman Sea between July 14th and 21st. The first of these will be during Sunday, the second on Monday, third on Wednesday, fourth on Friday and then possibly another weak front or trough system over the weekend. Each of these systems will likely produce strong winds across both Islands, with damaging to locally destructive winds over the Alpine and Mountainous terrain of the South Island. Snow is likely every single day this week over the South Island Alpine areas with snow down to medium levels possible on various days. 

 

Across the Alpine regions, snow combined with damaging to destructive winds of 100-140km/h will likely lead to dangerous whiteout conditions and heavy blizzard conditions at times. Heavy rain mixing with snow across the Alpine regions will also increase the risk of some avalanches, as loose snow is impacted by rain which causes the snow pact to slip. 

Forecast 10 day rainfall across New Zealand. Image via Windy. Pink >200mm, red >100mm, orange >50mm.

 

 

Across the course of the week or the next 10 days, 100-200cm is likely over the Alpine regions of the South Island with peak totals of 175-250cm expected. Rainfall totals of 100-200mm and locally up to 300mm is expected over the Western half of the South Island and scattered parts of the North Island, with other areas of both Islands seeing 50mm+. Most areas are expected to see damaging winds (blue shaded areas) of 90km/h+ over the course of the week, with gusts of 125km/h+ (destructive – yellow shading) possible over the Alpines. Overall, this may seem like a pretty tame week across the majority of Eastern areas of the South Island the the majority of the North Island in general – bit across the Alpine areas its going to get pretty crazy!

Wind accumulation (maximum wind gust over x amount of days) across New Zealand for the next 10 days – blue shading >90km/h, purple >100km/h as peak gusts. Image via Windy.