Thursday and especially Friday are warmer than average over a large chunk of the country by as much as four to eight degrees while overnight lows are either bang on average or above average for most – with the exception of only Northland this week which has been colder than normal overnight.
The warmer trend is a continuation of airflows coming out of Australia or the sub-tropics, rather than Southern Ocean southerlies.
However on Sunday a south to south west change moves up half of the country, with a temperature drop over the South Island in particular. The North Island has somewhat of a slight cool down with Friday’s high in Wellington around 16 or 17 degrees while on Monday it may fail to reach the teens with a current forecast high of 12 degrees.
The cooler change next week looks short lived though – we’re back to much warmer than normal weather by Thursday thanks to a sub-tropical flow.
3AM MONDAY SHOWS COLD AIR PEAKING OVER NZ:
NOON WEDNESDAY SHOWS THE SUB-TROPICAL FLOW SPREADING OVER NZ: