A weather bomb on February 24 caused widespread flooding and slips in and around Mangawhai, above on Waiteitei Rd, during Northland’s wettest summer on record.
A weather bomb on February 24 caused widespread flooding and slips in and around Mangawhai, above on Waiteitei Rd, during Northland’s wettest summer on record.
The Winterless North may have to change its moniker to the Summerless North after the region suffered its wettest summer season on record, with Whangārei recording more than a metre of rain.
It may come as no surprise to Northlanders, but December through February produced some of the heaviest downpourson record, according to the Niwa Climate Summary for summer, with Whangārei recording a whopping 1004mm of rain for the three summer months - just under four times the normal summer average and the highest summer total since records began in 1937.
As well, Whangārei recorded its highest-ever single summer day rainfall total when 216mm fell on the district on February 12. Whangārei recorded over 77 per cent of its annual normal rainfall during summer.
Kerikeri recorded its second wettest summer on record with 767mm - just over twice the normal summer rainfall - and Russell had its fourth highest summer rainfall with 624mm, again, just over twice the summer norm.
Niwa analytical meteorologist and forecaster Tristan Meyers said the summer of 2022-23 was characterised by contrasting weather extremes across the country.
It was exceptionally wet for the North Island, with Northland, Auckland, Bay of Plenty and Hawke’s Bay all having had their wettest summer on record.
Whangārei Quarry Gardens suffered major slips from Cyclone Gabrielle. Here garden manager Guy Hessell surveys some of the damage. Photo / Michael Cunningham
‘’During summer 2022-23, two ex-tropical cyclones impacted New Zealand. The first one, named Hale, occurred on January 10-11 and made landfall on the North Island. The second, Gabrielle, occurred over February 12-15 and resulted in historic flooding, widespread destruction to agricultural, horticultural and viticultural lands, dozens of impassable roads, severe coastal erosion, the country’s third-ever national state of emergency declaration, and loss of life.’’
Frequent heavy rainfall events saturated soils across the North Island and caused several bouts of flooding, which was particularly severe about Northland, Auckland, Coromandel, the Bay of Plenty, Gisborne, Hawke’s Bay, and Wairarapa.
Surface flooding on Porowini Ave and Kaka St, Whangārei, as Tropical Cyclone Gabrielle hits Northland on February 12. Photo / Michael Cunningham
The effects of ex-tropical Cyclone Hale were particularly severe in the northern and eastern regions of the North Island. Gisborne declared a state of local emergency as heavy rainfall led to flooding, slips, and road closures across Northland, north Auckland, Great Barrier Island, the Coromandel Peninsula, and Gisborne.
Between January 27-28, torrential rainfall affected a large portion of the northern North Island, including Northland.
Then from February 12-14, Cyclone Gabrielle caused 11 fatalities and a range of other devastating impacts in New Zealand. MetService issued red weather warnings for rain and/or wind in Northland, Auckland, the Coromandel Peninsula, East Cape, and Taranaki.
Numerous downed trees and flooding were reported in Northland, particularly in the Whangārei area, and more than 20,000 households were reported to have lost power in both Northland and Auckland.
Some of the impact of Cyclone Hale on Northland - one of two cyclones to hit the region over summer
And on February 24, a front became stalled across Auckland and southern Northland. Converging winds associated with this feature, as well as an upper-level low-pressure system, allowed it to become the focal point of widespread heavy rain and thunderstorms. Early in the afternoon, a thunderstorm led to intense downpours near Mangawhai, leading to flooding, road closures, and serious property damage.
A Northland Regional Council rain gauge “Hakaru at Tara” recorded an incredible 24-hour rainfall total of 380mm between the morning of February 25 and the next morning - more than 670 per cent of the February normal in nearby Mangawhai.
The nationwide average temperature for summer 2022-23 was 17.9°C (1.1°C above the 1991-2020 average from Niwa’s seven-station temperature series which begins in 1909), making summer 2022-23 the third-warmest summer on record.
A road closure at Mangawhai during Cyclone Hale - contributing to Northland’s wettest summer on record.
Jackie Fanning, a teacher from Mangawhai, lost her home in a landslide caused by torrential rain that fell on February 24, causing widespread flooding, slips and road closures around the town.
Piri Tangira, from Ōpua, and Margaretann Robinson, from Whangārei, move a downed tree blocking State Highway 11 at Lemon’s Hill, during one of Northland’s summer storms. Photo / Peter de Graaf
