Warm and windy weekend increases risk of heatwave conditions
Ongoing hot weather will peak at the end of this week, with MetService forecasting temperatures in the mid-thirties for towns on both Islands on Sunday and Monday. The extra boost to the already-warm and above average temperatures comes from a slab of humid air sliding towards New Zealand from the tropics this weekend in a northwesterly windflow.
As well as warm; it will be windy, as those northwesterlies bring gales to the mountains and exposed areas near the coast. MetService already have several Strong Wind Warnings in place, and although the wind will ease on Friday, it will be coming back with a vengeance on Saturday. In addition to this, the humid air will bring persistent heavy rain to the southern West Coast and Fiordland between Sunday and Tuesday, where slips and surface flooding will be possible.
Meteorologist Tom Adams explains “The combination of warm, humid air with strong northwesterly winds leads to a marked heating effect in eastern areas. This will add several extra degrees to the already high air temperatures. Unfortunately, these warm temperatures will stick around at night too, meaning uncomfortably muggy conditions to sleep in.”
It will be Tuesday at least before a cold front sweeps away the muggy air from the South Island, and the front then weakens over the North Island so warm temperatures are likely to continue there well into next week. This means that several locations are likely to meet heatwave conditions, where daily maximum temperatures exceed monthly averages by five degrees for five or more days in a row.