High pressure often means drier weather, but not always sunnier. At this time of the year high pressure systems (known as anticyclones in the Southern Hemisphere, with the airflow being anticlockwise around the centre) don’t always guarantee sunny skies, with the nights still longer than the days and sea temperatures still fairly mild compared to overnight air temperatures.
High pressure helps keep cloud trapped down low – unable to move over the ranges of New Zealand smoothly – it makes for a very cloudy build up for some coastal areas. Higher up inland areas tend to be sunnier (although fog patches are possible).
At the centre of large highs there is very little air movement/wind to push the clouds along – which means the overcast weather is hard to clear away. Sometimes you get light mist or drizzle patches, barely enough to wet the ground.
Cities like Auckland, Hamilton and Palmerston North are often most exposed to anticyclonic gloom with low cloud off the Tasman Sea unable to lift up and over the hills and ranges to the east. But anticyclonic gloom can happen in all coastal parts of NZ.
Our weather graphs at RuralWeather.co.nz have a fog and cloud forecaster – helpful at planning around this gloomy weather and letting you know when the sunnier weather may return again.
WeatherWatch.co.nz / RuralWeather.co.nz