Keeping an eye on the tropics

February 22, 2016

A ridge of high pressure saddles New Zealand, keeping the weather settled for most of us through the beginning of this week. A wet front moves onto Fiordland on Wednesday bringing heavy rain, and the remnants of Tropical Cyclone Winston may affect central and northern areas of New Zealand this weekend.

Although high pressure sits over the country bringing sunshine and warm temperatures to most, there is some low cloud and drizzle about, mostly for east coast areas, thanks to the moisture trapped under this high. On Wednesday, the front that moves onto Fiordland will be slow moving and will bring rain with heavy falls to the southwest corner of the country spreading as far north as the Glaciers.

Temperatures in the east warm up in the second half of the week, getting into the high twenties, while the rest of the country will be  cooler in the low to mid-twenties. More humidity arrives from the tropics affecting the north toward the end of the week, with overnight forecast minimums of up to 20 degrees and eastern areas of the North Island getting maximum daytime temperatures into the 30s.

Tropical Cyclone (TC) “Winston”, currently category 4, is forecast to turn in a more southerly direction today, and in the latter half of the week is expected to evolve into a deep mid-latitude low. You can find a MetService blog about this transition process at “Looking at the latest global weather models”, said Communications Meteorologist Lisa Murray, “there is an increased risk that this low could impact central and northern New Zealand during the coming weekend.”

With tropical cyclones there is always some uncertainly associated with the tracks they will take, and the global weather models can change considerably from day to day until the track becomes stable (where the models are in more agreement).  If this low does affect New Zealand, it has the potential to be a significant weather event, and could include impacts such as increased sea swell, heavy rain which could cause flooding as well as damaging winds.

Currently it is too early to give an accurate forecast for which regions of New Zealand are likely to be impacted, but MetService meteorologists are monitoring this situation closely and will keep you updated. What we can say is that it will not have the same impact and level of destruction as it did in Fiji. Any severe weather effects for New Zealand caused by this deep low will be included in Severe Weather Warnings, Watches and Outlooks, as well as marine warnings and forecasts. MetService advise people to keep up to date with the latest forecasts at

Official Severe Weather Watches and Warnings are reviewed and re-issued by MetService at least every twelve hours, and more often if necessary. To get the most up to date information on severe weather around the country, or any other forecasts, see or on mobile devices at You can also follow our updates on MetService TV, at MetService New Zealand on Facebook, @metservice and @MetServiceWARN on Twitter and at 

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