The ridge over Aotearoa New Zealand weakens as a deepening low in the north Tasman Sea approaches the country tomorrow
(Tuesday). MetService is forecasting the low to move southeast over the country on Wednesday, bringing rain with heavy
falls to the North Island and upper South Island. Meanwhile, the remainder of the South Island remains dry in the east,
but rain or a few showers affect the west and Far South.
Rain and strong north-easterly winds develop over Northland Tuesday morning, spreading southwards to Taupo by the end of
the day and over the remainder of the North Island early Wednesday as a deep low crosses the country. A Severe Weather
Warning for Heavy Rain has been issued for Bay of Plenty including Rotorua, with 80-120mm of rain expected to
accumulate, especially about the ranges. Heavy Rain Watches have also been issued for Northland, Auckland, Coromandel
Peninsula and Mt Taranaki.
MetService Meteorologist Amy Rossiter said, “There is also a moderate risk of thunderstorms over Northland during
Tuesday afternoon and evening, which then extends towards Auckland at night and into Bay of Plenty on Wednesday.”
After a few chilly nights recently, the low pulls some warm and humid air from the tropics down over the North Island,
with temperatures overnight Tuesday expected to be above average.
“Models are forecasting Whakatane to be well above average with a minimum of 18 degrees overnight Tuesday.” Rossiter
said.
Over the South Island, rain is expected to develop in the northwest of the South Island Tuesday evening and spread into
Marlborough for a time on Wednesday as the low moves southeast across the country. Further south, eastern regions remain
dry while western areas continue to see a few showers or rain in the onshore flow, clearing for a time on Wednesday. A
front also approaches the Far South on Wednesday bringing brief scattered rain to Southland and Clutha, before becoming
slow moving and weakening away early Thursday.