Incoming Rain But A Mainly Fine Weekend
Early next week MetService is forecasting a low-pressure system to bring rain to dry North Island areas. This system will see reasonable rain accumulations for many regions but is by no means a drought breaker. Before that system arrives, a front affects the South Island’s west coast tonight, and MetService has issued an Orange Heavy Rain Warning. This front weakens as it moves north, and a ridge of high pressure brings a mainly fine weekend across Aotearoa.
MetService meteorologist Andrew James explains, “The front arriving today could cause problems down south – we’re expecting up to 200mm in the ranges of Fiordland and up to 150mm for parts of the Otago Headwaters over the next couple of days. That system moves north and weakens quickly. A watch is in place for heavy rain as far north as Fox Glacier, but we don’t expect anywhere north of Greymouth to be affected by that front.” Additionally, a strong wind watch is in force for Fiordland and Southland.
Kiwis can however expect a mainly fine weekend. There is some morning cloud and frost expected for inland North Island and coastal South Island areas. Eastern parts of Northland and Gisborne are in for a light shower or two. Saturday is the better day for outdoor activities before winds pick up on Sunday. These winds also stop it being so cold at night – temperatures will be noticeably warmer than recently overnight on Sunday.
Beyond the weekend, low pressure is expected to provide some much-needed rain relief to parts of the North Island. James explains, “The low rolls in from the northwest and the rain starts late on Sunday, then spreads east on Monday. Western dairy-farming areas from Waikato to Taranaki are in line for a decent dose, but most of the island will see some rain. It has been extremely dry right across the North Island this year, with many places tracking at less than half their normal year-to-date rainfall following a drier than average 2019, so this rain will be good news for many.”
Auckland and Northland are set to receive a much-needed top up on Sunday and Monday – with similar amounts to the last good rain in early May. However, given the current levels of dryness it won’t be enough to solve Auckland’s water woes and water restrictions will remain in place. Auckland’s dams are only at 43.1% of capacity on the back of the driest October-April period on record. The airport weather station recorded 254mm during that time, only 46% of the October-April normal, in observations since 1963.
Farther east, Coromandel and Bay of Plenty are also expected to get a decent burst. This is great news for Whitianga, who had a record dry start to the year, with 78mm observed from January - April 2020. This is the lowest January-April total on record, in observations since 1941.
However, this system isn’t the saviour for all regions. “Sheltering of the ranges mean Hawkes Bay and Gisborne might not get very much rain out of the low. The South Island’s east coast is really dry from Mid-Canterbury to Otago, and this area won’t receive anything from either the low or the front,” James said.