Soil moisture levels are likely to increase along the West Coast and in parts of the lower South Island during the next week, while most other areas will see little change.
Across the North Island, moderate to large increases in soil moisture levels were observed in most locations due to substantial rainfall in the past week.
Due to the anticipated below normal rainfall and above average temperatures in the next week, soil moisture levels are expected to decrease farther in many locations across the North Island.
Hotspots in the North Island are currently found in Aupouri Peninsula, interior Manawatu-Whanganui, and interior Hawke’s Bay. In the South Island, only subtle soil moisture changes were observed in the past week.
A weekly update describing soil moisture across the country to help assess whether severely to extremely dry conditions are occurring or imminent. Due to the anticipated rainfall amounts over the next week, soil moisture levels will likely increase at least slightly across much of the North Island.
Conversely, the lower east coast and the far south (including Hawke’s Bay, coastal Wairarapa and Wellington) saw a soil moisture increase due to rainfall totals above average for the time of year.
However, hotspots remain in place across western Northland and Aupouri Peninsula, a small portion of central Waikato, southern Manawatu-Whanganui, and much of Wairarapa and southern Hawke’s Bay. In the South Island, soil moisture levels generally did not change significantly in the past week.
The driest soils across the North Island compared to normal for this time of the year are found in central Taranaki District and parts of western Waikato where the soil moisture levels continue to be well below average for this time of year.
Outlook and Soil Moisture In the North Island, rainfall amounts during the next week could be highly variable due to uncertainty regarding the interaction between moisture from Tropical Cyclone Oma and a separate area of low pressure expected to form near New Zealand on Sunday and Monday (24-25 February).
Across the South Island, soil moisture levels decreased during the past week with meagre rainfall in the north and east.
Across the South Island, soil moisture levels generally decreased in northern areas, although small improvements were observed in interior Otago, Southland, and Stewart Island.
The driest soils in the North Island compared to normal are currently found in the eastern Far North District, around New Plymouth, and coastal Horowhenua. Across the South Island, soil moisture levels generally increased in Southland and the lower West Coast and remained constant or slightly decreased elsewhere.
Across the North Island, soil moisture levels generally decreased during the past week due to lower than average rainfall for this time of year.
With the rainfall amounts anticipated in the next week, additional soil moisture improvements are likely parts of the central and eastern North Island with the greatest potential for soil moisture increase from the eastern Bay of Plenty through to the Hawke’s Bay regions, particularly in the higher terrain.
In the North Island, another week of substantial rainfall is likely in many areas, which could lead to further soil moisture improvements. With substantial rainfall amounts anticipated in the next week, additional soil moisture improvements are likely in the northern half of the North Island.
Across the South Island, soil moisture levels generally did not change substantially in northern areas this past week, but soils in central and southern areas continued to get much wetter than normal thanks to more heavy rainfall in recent days.
With the rain amounts expected in the east and north, soil moisture levels are anticipated to improve in the next week, while soil moisture should stay near constant or slightly decrease in the rest of the island where many locations will see total rain amounts less than 15mm.