Wrapping up a very wet week.
Over the last few days, a slow-moving rain band bought some very large rainfall accumulations to places in the east of
the South Island that typically don’t see a large amount of rain at this time of year.
From Thursday, a low pressure system near central New Zealand funnelled a stream of humid air towards the east coast of
the South Island. This system was slow moving and delivered persistent and heavy rain to the area, causing flooding,
slips and road closures. Most places from Christchurch to Dunedin recorded more than the long-term average July rainfall
in just 24-48 hours. “In some places this comparison was even more stark: The weather station at Oamaru airport reported
147mm throughout the event, which more than triples the July average rainfall of 40mm.” said MetService meteorologist
Angus Hines. Due to the severe weather and flooding, a state of emergency was called in many South Island towns and
cities, including Christchurch.
As the clean-up from this event gets underway, Sunday is a clear, dry day for much of the South Island. However, cold
temperatures and excess rain water have created conditions favourable to the formation of black ice in sheltered and
shady spots. This is likely to be the case again in the coming night, so drivers are advised to be alert on the roads.
Elsewhere, showers and cloud are affecting the fringes of the North Island, and the top of the country from Auckland
northwards, but a decent day is in store for most places in between.
A pair of fronts are in line to move northwards over the South Island over the coming few days, this time bringing the
heaviest rain to western areas. A heavy rain warning is in place for a burst of heavy rain in Fiordland early on Monday
morning, while a Severe Weather Watch for heavy rain has been issued further up the west coast. Drenched places in the
South Island will briefly see scattered rain on Monday, although nothing like the intensity of the rain they have had in
the last few days. Another brief dry spell looks likely after this, but all eyes will be on the forecasts for Thursday,
when another cold southerly rain event looks likely to affect Canterbury and much of the South Island.