Agencies forecasting wet start to Easter holidays

A109 Light Utility Helicopter flight with mayor Gisborne City from the air in November 2023.

Predicting the weather for this weekend is a bit like guessing what’s inside an Easter egg.

New Zealand’s climate agencies have hedged their forecasts because of a low expected to concentrate off East Cape by the end of the week and direct moist southeasterlies over northern New Zealand.

MetService forecasts a change to cooler south-easterly conditions on Friday, with rain developing in the morning.

Saturday’s forecast is for the rain continuing and southerlies, but MetService expects Sunday to be clear and fine with northwesters and Monday to be partly cloudy with northerlies.

MetService says there is moderate confidence of warning amounts of rain for Gisborne and Wairoa on Saturday.

On Sunday, the low continues to move away to the east of the country, with the southeasterly rain clearing.

The National Institute of Water and Atmospheric Research also notes a “subtropical low moving to the north-east of the North Island” bringing a change to the weather.

Niwa forecaster Ben Noll says it looks like this will bring some rain, but “might stay just far enough offshore that we don’t receive copious amounts”.

Most weather models show the low bringing onshore rain to the Gisborne East Coast area — particularly the coast north of Gisborne.

Meanwhile, climate scientists are assessing the likelihood of an El Nino developing over winter.

United Kingdom and US scientists are worrying about the possibility of a major El Nino, which would bring drought to regions such as the Gisborne-East Coast. The remnants of La Nina still linger in the southwestern Pacific but some climatologists are pessimistic about a strong El Nino emerging.

Locally, MetService and Niwa have issued medium-term forecasts for the next month to three months.

For the Gisborne district, Niwa says temperatures are equally likely to be near average (a 40 percent chance) or above average (a 45 percent chance).

Niwa also warns some sub-tropical or tropical low pressure systems could still track near the Gisborne-East Coast region, occasionally increasing the risk for heavy rain.

MetService says climate prediction models are increasingly pointing to El Nino developing in the latter half of winter and into spring, “which would signal a colder and more unsettled spring as frequent southwesterlies spread across the country”.