Thick high cloud has this afternoon advanced southwards over northern New Zealand turning blue sky into dreary grey ahead of another sub-tropical low which threatens to bring more flooding to the north of both islands.

WeatherWatch.co.nz forecasters have advised Northland residents in flood prone areas to have enough fresh water and food for three days with a moderate possibility of flooding and slips in some areas starting from tomorrow afternoon and lasting until Tuesday morning.

While flooding isn’t expected to be as severe as what Hawkes Bay has just received the rainfall predictions are certainly high.  The government forecaster is warning up to 200mm of rain may fall between noon Monday and early on Tuesday in the hills and ranges of Northland.  

The low, which originated over the Coral Sea, is packed with moisture and its journey will be slow due to a blocking high currently over most of New Zealand.

Rain clouds will be slow moving over the upper North Island and WeatherWatch.co.nz says low lying areas of Northland, Cormandel and Bay of Plenty may experience slips and some flooding over the next 48 hours as the system moves by.

WeatherWatch.co.nz says there is also a risk of rain heavy enough to cause some flooding in vulnerable parts of the Auckland region too and advises motorists to be aware of surface flooding particularly on Monday.

Following recent heavy rain Coromandel Peninsula and Bay of Plenty may be more vulnerable to further rain related problems.

The large high will guide the low away from New Zealand on Monday and out into the central Tasman Sea, however as the high continues to depart New Zealand the low should curve back around and towards the South Island.  Despite the centre of the low moving out to sea the rain bands are still likely to line up over land.

Our belief is that Mt Taranaki and the Nelson ranges remain at a high risk of heavy rain on Tuesday or Wednesday as the low moves towards the West Coast.

The government forecaster is also indicating heavy rain in these regions, particularly the Nelson region which they have “moderate” confidence of heavy rain on Tuesday. 

Metservice has high confidence of heavy rain in Northland, Auckland, Coromandel Peninsula and Bay of Plenty for Monday and Tuesday.

WeatherWatch.co.nz says wind may also be an issue with gales predicted for exposed parts of Northland, coastal Auckland and the eastern Waikato later on Sunday or Monday.   WIth the centre of the low tracking out into the Tasman Sea it reduces the risk of those gales becoming severe gale.

– WeatherWatch.co.nz