The Gisborne district is
"scarily dry" and the fire risk is much higher than people
realise, thanks to a month of drying wind and a near-record
National Institute of Water and Atmospheric Research
monitoring shows the Gisborne district is by far the driest
place in the North Island.
Principal rural fire officer in Gisborne Rene Londeman said
the countryside was "scarily dry" and within the month,
hilltops have gone from green to brown in many places.
MetService rain data shows that even with the rain of the
past few days, Gisborne has had the all-time driest October
since official records began in 1937.
That was in 1961, when just 20mm was recorded over the month.
Evapotranspiration - the rate at which moisture is sucked out
of the soil by wind and sun - has been running at between
three and four millimetres for most of the month.
Mr Londeman says the dry-off has started early and there is a
lot of fire fuel along roadsides, under trees and along field
edges, with dead vegetation and dry grass the real worry.
"This last drop of rain - just a few millimetres - has really
done nothing. One sunny day and a bit of wind, and we are
back where we started."
Roadside vegetation is a particular concern and Mr Londeman
said this had gone from green to yellow very quickly.
There had been strong north-westerlies throughout the month,
and soils had dried and baked hard.
Irrigation systems have been laid out and are already working
to stop seedlings dying before their root systems can reach
below the dry layer.
Mr Londeman said the Gisborne-East Coast district has had the
greatest shortage of rainfall in the whole country over the
past month and this is confirmed by Niwa monitoring.
The soil moisture deficit as of October 28 had passed the
80mm mark - passing 70mm is usually taken as heading towards
Niwa data shows the Gisborne-East Coast district from Mahia
to East Cape has had just 10 to 20 percent of its usual
rainfall, and on top of that it has had 125 percent of its
These factors have combined to push the mean temperature to a
degree and a half warmer for the country between Opotiki,
Gisborne and Tolaga Bay, and half a degree warmer at the
Ruatoria end of the district.
The Eastern Bay of Plenty into the Waioeka Gorge area is
rated severely dry, while this side of the ranges is still
rated moderately dry, according to the Standard Precipitation
Index that measures current conditions against the 1981-2010
Niwa's three-month outlook for October to the end of December
is for warmer-than-usual temperatures but near normal rain
The strong nor'westerlies and highs positioned over the top
part of the country can be a sign of an El Nino in the wings,
and some climate models have indicated this possibility,
although current El Nino Southern Oscillation analyses say it
is still in a "neutral" state.
- By the Gisborne