Yet another sub-tropical low is deepening today and is looking likely to bring another period of torrential rain and gale force winds to parts of the North Island, mainly the north east.

WeatherWatch.co.nz says the low developed near New Caledonia on Tuesday and will quickly track south towards northern New Zealand today.  It is smaller than the low from Monday but following the saturating rains of the previous low this one is worth monitoring.

This next low is caught up in the jetstream to the north of New Zealand – and is associated with a number of significant rainmakers hitting northern Australia, although this low is newly forming.

“This new low is rich in tropical moisture and brings yet again the threat for flooding – and this time localised flash flooding may also be an issue” says head weather analyst Philip Duncan.  “The ground is already saturated and the rain band that’s coming down may be faster moving but it also contains much heavier bands of rain”

“A few hours of torrential rain could lead to rapidly rising rivers and streams, especially in the upper north and north east which is already saturated from Monday’s sub-tropical low”.

WeatherWatch.co.nz estimates the period for severe weather may be as little as 6 hours, compared with over 24 hours with Monday’s sub-tropical low.  “This will be shorter and sharper and less widespread – with some of the worst weather actually occurring just offshore from Northland and Auckland”.

Mr Duncan says Bay of Plenty and East Cape may be directly in the firing line of the low while Northland, Auckland, Coromandel Peninsula and eastern Waikato may also receive 6 hours of heavy rain and gusty winds.  Normally not a newsmaker, but on top of the recent heavy rains it is.

The low will fade out on Friday ahead of a Southern Ocean low which will bring a strong to brisk westerly change across the nation this weekend – and more rain for the country this weekend”.

– WeatherWatch.co.nz