Hotspot Watch 27 February 2020
The 2013 drought affected the entire North Island plus the west coast of the South Island. This year the impact wasn’t quite as extensive but did range from the Far North to Canterbury. Auckland has been particularly hard hit with more than 77 consecutive days spent in drought or severe drought, according to the New Zealand Drought Index. In 2013 the region experienced 58 consecutive days of drought. A number of North Island locations recorded their driest January-April on record this year, including Whangarei, Auckland, Whitianga, Hamilton, Tauranga, Whakatane, Napier, and Taupo.
“For some parts of the country this year’s drought was similar to the one in 2013 which was the worst in 40 years. This has hit hard, far and wide,” he says.
Other regions hard hit by drought this year include the Far North, Waikato, Gisborne, Hastings and Marlborough.
The most consecutive days in drought or severe drought during the longest droughts since 2007 are (according to the NZ Drought Index):
- Far North District: 72 days (2009-10), 65 days (2020), 40 days (2013)
- Auckland: 77 days (2020), 65 days (2010), 58 days (2013)
- Waikato District: 63 days (2013), 61 days (2020), 52 days (2014)
- Gisborne District (west): 47 days (2013), 37 days (2020), 12 days (2015)
- Hastings District (west): 33 days (2013), 29 days (2020)
- Marlborough District (south): 35 days (2020), 9 days (2019)
Despite this, soil moisture levels generally decreased slightly during the past week, particularly in the Far North and from Waikato to Hawke’s Bay. The driest soils across the North Island, when compared to normal for this time of the year, are generally found in the northern half of the island along with Wairarapa, while the wettest soils for this time of the year are located in Kapiti Coast.
There was also a lack of moist, northerly air flows and a persistently positive Southern Annular Mode early in the year which was associated with more tranquil weather in the New Zealand region.NIWA climate scientist Petra Pearce says this year’s drought highlights the projections from NIWA’s regional climate modelling for northern and eastern areas of New Zealand (particularly the North Island) to become more drought-prone with ongoing climate change over this century.
“Average rainfall is projected to decrease for those areas, particularly during spring and summer, which combined with increased temperatures (and therefore greater evapotranspiration/uptake of water by plants) is likely to result in more frequent and severe droughts.”
Hotspot Watch 18 March 2020