“I do have to bring the bad news that there is more rain on the way.”
Significant rainfall is forecast to hit Northland on Tuesday and then move south towards Auckland later that day or early on Wednesday.
The bouts of rain are expected to be heavy and could cause more slips and widespread flooding in Northland.
Hines said last Friday’s weather event in Auckland saw about a 50 per cent increase in rainfall in the region for any day since rainfall tracking started 60 years ago.
When asked if it was a freak weather event, he said it was really hard to pinpoint and predict the volume of rainfall in Auckland.
Auckland and Northland remain at an Orange warning level, with heavy rain warning and severe thunderstorm watch in place.
A slow-moving front drifting west should pass over Auckland and Northland this morning bringing possible thunderstorms, some of which may be severe.
In Northland, a further 30 to 60mm of rain is expected to fall in the north and east of the region, with lesser amounts in the west.
However, MetService says localised areas may receive between 70 and 100mm.
“Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.”
Auckland’s forecast is for a further 20 to 40mm of rain north of the city, with possibly 40 to 80mm in localised places and downpours reaching 40mm/h. Thunderstorms are possible.
Although less rain is likely south of the city, MetService says the rainfall amounts could still exceed the warning criteria in some places.
Another period of heavy rain is in the forecast on Tuesday for both Auckland and Northland, another warning will probably be issued closer to the time.
Yesterday, MetService meteorologist Georgina Griffiths told media that Auckland faced a “hang-in-there type of situation”.
“We are very vulnerable in the region at the moment to any rainfall ... rainfall that normally would not cause problems is exacerbating slips and causing localised flooding.
“We’ve already had some minor rainfall heavy showers in the southeast this morning, and we’ve had some problems.”
Because of that, MetService had lowered its normal thresholds for heavy rain for the region.
She said today (Monday) would bring a little reprieve and encouraged Aucklanders to use the break to prepare for a “potentially significant” system arriving later Tuesday or during Wednesday.
“Given the region’s vulnerability, we may not need much rain in Auckland to see some impacts from a flooding slip point of view.”
Niwa weather forecaster Ben Noll said details of that later-week event were still coming through, “but it looks like we could be in for another intense atmospheric river event for the North Island”.
An atmospheric river is a phenomenon that brought about Auckland’s wettest day in history last Friday.
Chris Brandolino from Niwa said the weather system has come from the tropics, and the atmospheric river was driving the humid, sticky conditions in Auckland.
“The morning is going to be the wettest part of the day for the upper North of the Island.”
He said the afternoon should be drier, but could still be wet.