Unseasonably high temperatures

By Roger Childs

Driving through Waikanae at 3.00pm on Thursday the car indicated it was 27° C outside. Two hours later along Marine Parade in Paraparaumu Beach it was still high at 26° C. But it’s only November, which is theoretically the last month of Spring.

We’ve also had ten days in a row of fine weather which is probably more than we had all last summer.

So are we in for great weather over the holiday period, unlike 2016-17?

The year without a summer

For Kapiti and Wellington people there was virtually no summer last time around. There were possibly a dozen days when the beach beckoned, compared with over sixty in the early months of 2016.

In mid March, Wellington sunshine hours for the first 70 days of the year were nearly 100 behind 2016. The pattern continued, and by August the capital was over 200 hours down. Now there is some claw back.

We are doing well in mid-late November because we have a big H over the country. This means there is high pressure, anti-cyclonic weather, which is invariably dry and sunny.

A month ago much of the country, especially on the western side, was sodden and any extra rain just sat on the surface because of high water tables. Farmers were feeding out precious hay and silage, but they are now irrigating their pastures and crops, and town folk are watering their gardens.

It doesn’t take long for things to turn around!

A long hot summer ahead?

Quite possibly, but certainly better than the last one. So much depends on the circulation of currents in the huge Pacific Ocean. The temperatures of the sea in different places are crucial, as these determine the inter-relationship between high and low pressure s systems.

However, the origin of the high pressure systems, such as the one affecting us now, is central Australia and if they keep coming our way over the summer months we will get plenty of beach weather.

Readers will recall the devastating hurricanes which affected the Caribbean and Southern USA in their late summer months. These resulted from intense heating of the mid Atlantic Ocean creating centres of very low pressure.

The same thing could happen in the Pacific as ocean temperatures rise, especially in February and March. What we call tropical cyclones, can be catastrophic for the Island nations to the north and also cause severe weather in New Zealand, if they veer south.

However, NIWA expects that in the next couple of months the Kapiti / Horowhenua / Manawatu area will get

• higher than usual temperatures
• rainfall and soil moisture conditions close to average.

So hopefully this will mean plenty of sunshine, and enough precipitation to keep farmers and gardeners happy!