Ferris said there is potential for localised and heavy bouts of rain on already saturated soils.
MetService would be keeping a “close eye” on the forecast.
‘Risk of frost’
Temperatures are also expected to plummet this week.
MetService forecaster Mmathapelo Makgabutlane said southerly winds were set to sweep up the country today.
“Compared to last week, the general feel of the air will be much cooler, and it is looking like the trend for the rest of the week.”
Parts of both islands could also see frosts, she said.
On X, MetService told people to “cover those cabbages”.
“Overnight there will be a risk of frost for most of the South Island and inland areas of the North Island,” it posted.
“Allow extra time for your morning commute because the roads could be icy.”
Makgabutlane recommended those attending Anzac Day dawn services wrap up warm, as a chilly start to the day has been forecast.
Auckland is forecast to reach a high of 20C and a low of 13C on Anzac Day, while Hamilton is set to reach 19C with a low of 7C.
In the South Island, Christchurch is forecast to hit a high of 16C and a low of 5C, while Dunedin will reach a high of 16C and a low of 9C.
Risk of weather warnings this weekend
The MetService severe weather outlook for Saturday says there’s a moderate chance of warning amounts of rain for Northland and upper Auckland regions.
“A large high over the country moves slowly eastwards, while a trough affects the north of the North Island, bringing rain and strengthening northeast winds.
“Another trough is expected to approach the far south of the South Island late in the day. This should bring rain to the west of the island and strengthening northwest winds to the southeast.”
On Sunday there’s a moderate chance a heavy rain warning will be required for the southeast of Northland, Auckland north of Whangaparāoa, Great Barrier Island and the far north of Coromandel Peninsula.
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