Heavy rains and strong winds are expected across the upper North Island over the next couple of days.
MetService last week said it was likely Monday would see the first formal weather alerts of the year, and that has come to pass.
The first is a heavy rain watch for Northland, from 7am Monday through to 10am Tuesday.
“Periods of heavy rain are expected north of Kaikohe from Monday morning, especially in the east,” MetService said.
“Heavy rain is expected to become more widespread through Northland from Monday evening onwards. Rainfall amounts may approach warning criteria. Thunderstorms and localised downpours are possible, especially from Monday evening. Moderate chance of upgrading to a Warning.”
Heavy rain watches are also in place for Auckland and Great Barrier Island (1am-1pm Tuesday), and for Coromandel (4am-6pm Tuesday).
“Periods of heavy rain. Amounts may approach warning criteria, especially in the ranges,” MetService said. “Moderate chance of upgrading to a Warning.”
Strong wind watches are also in place for Northland (1am-8am Tuesday, up to gale-strength easterlies in exposed places) and Auckland/Great Barrier Island/Coromandel (5am-11am Tuesday, also easterlies approaching gale strength, with a moderate chance of being upgraded to a warning.
Rain warnings are issued when the expected rainfall will be greater than 50mm within six hours or 100mm within 24 hours. A watch is issued when forecasters expect “conditions may deteriorate to the thresholds”.
Wind warnings are issued when speeds are expected to exceed 90km/h or there will be frequent gusts exceeding 110km/h.
The thresholds can be adjusted temporarily “in collaboration with regional authorities to support more effective readiness, response or recovery activities”.
NIWA, which will take over MetService in a merger announced by Science, Innovation and Technology Minister Judith Collins last year, said “a downhill trend for the top of the North Island” was incoming thanks to a low-pressure system.
rnz.co.nz
