The forecast for the last day of 2020 looks fairly settled – but may not be dry for everyone.
Weak high pressure should cover New Zealand with no nearby significant storms or lows, so that means winds shouldn’t be too strong. Perhaps a bit of a north east breeze down the eastern South Island while elsewhere variable winds and afternoon sea and lake breezes.
This set up does tend to favour showers/downpours developing in the afternoon and clearing in the evening around the inland South Island, especially near the ranges, and also across the upper North Island. Potentially with a few isolated thunderstorms.
Most main centres look dry although Queenstown and maybe Hamilton may be exposed to a downpour – the hourly forecasts we have in your local area + the rain forecast maps will be the best way to track possible wet weather risks on December 31.
As we switch gears into 2021 this weak high pressure is replaced by weak low pressure and this will generate a circular (clockwise) airflow around the nation bringing in various cloudy and wet areas – but still plenty of dry spells, especially in the North Island.
There are some signs that January 2021 will have better chances of rainmakers for dry northern NZ thanks to La Nina. Many parts of the upper North Island have been in a rainfall deficit for nearly two years now and rain is needed.
We’ll have more details about January’s expected rainfall in our next Climate Update, issued on December 31.