Updated 7:55am Tuesday — Heavy rain continues for parts of the North Island, including dry eastern and southern parts. The South Island may get brushed with it in the east, but rainfall totals look much lower there compared to the North Island. In fact a large portion of the South Island is drier than average for the middle portion of May.

Hawke’s Bay and Gisborne areas may receive 80 to 200mm over the coming days, mostly in the ranges but low lying areas have some potential too. This is heavy enough to cause slips, localised flooding and road closures.

As we’ve said for a week now, this low is a ‘messy’ system (in fact even in the past 48 hours global modelling has been different in each update and from each provider) – so heavy rain will likely be broken into pieces. Our mountains and ranges play another roll at increasing totals and lowering them…so any slight movement in airflow can alter rainfall. Another reason why a low with sometimes two centres makes it more complicated.

There will be rainfall variety within regions with some areas only getting 5 to 20mm, others potentially in line for 100 to 200mm (especially around the eastern ranges of the North Island). See our weather videos for more details. Our next video update will be published around lunchtime Tuesday and we’ll be seeing just how long this low pressure zone will linger this week before the next big sou-west flow and high pressure zone move closer.

View 7 day cumulative rainfall maps here.

MetService warnings and watches here.

• WeatherWatch.co.nz

🌀🌀⚠️The incoming low has more than one centre, splitting energy & making for "blobs" of heavy rain (but drier nearby). The messy system may feed rain into the eastern NI for days.

Warnings/Watches need to cover areas larger than the severe weather to manage this uncertainty. pic.twitter.com/ONVyMGz6Ip

— WeatherWatch.co.nz (@WeatherWatchNZ) May 20, 2024

• WeatherWatch.co.nz