Peak waves in Haumoana to reach warning criteria as remnants of Lola approach

Heavy swells across Hawke’s Bay will be at their worst at Haumoana, where they are expected to reach 1.9 metres overnight as strong winds sweep in.

Rapidly rising waterways and hazardous driving conditions are likely for Hawke’s Bay as the remnants of ex-tropical cyclone Lola travel down the North Island.

MetService upgraded its rain watch in Hawke’s Bay to a rain warning on Monday morning, affecting the inland ranges south of State Highway 5 for 27 hours from 2pm on Monday to 5pm on Tuesday.

The MetService forecast said to expect 110-140 millimetres of rain with peak rates of 10-20mm/h, but 15-25mm/h on Tuesday afternoon during possible thunderstorms.

“Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous,” the MetService warning said.

Hawke’s Bay Civil Defence Emergency Management Group said in a post on social media it was monitoring the situation and would give an update if there were any further developments.

“HBRC [Hawke’s Bay Regional Council] advise forecast rainfall totals are less than [the] five-year [warning criteria] and are unlikely to cause any significant issues on the major rivers. However, this could cause some localised ponding and roading issues,” the post said.

The post said some heavy swells were expected, but the forecast peak wave heights for measured near-shore sites were mostly below warning criteria outside of one location.

“The only exception is the Haumoana area, where the peak wave height is predicted to reach the one-year warning criteria [1.9m] overnight, combined with strong winds. The swell is expected to slowly drop off over the following few days.”

Hawke’s Bay Regional Council said in its own media release of the rain warning for parts of the region: “Although the forecast rainfall totals over the next few days are less than a 1:5 [one-to-five-year] event.” It said there is a 20 per cent chance in any year of the river levels rising over the berm to the base of the stopbanks.

You can also keep track of levels on HBRC’s river level page at: www.hbrc.govt.nz/environment/river-levels/.

MetService predicted a trend to warmer temperatures in the middle of the week for Hawke’s Bay, before a plunge back into a new low system brings some rain on Thursday and Friday.

Thousands were left without power in areas in the north of the country, including Auckland, while the region was being lashed with wild seas and wind gusts.