Not everyone this weekend in New Zealand has a storm coming, despite some dramatic headlines and forecasts elsewhere. While we are in for a rough patch of weather in the days ahead most regions will be storm free and severe weather free.
Many people may be aware we have a Tropical Cyclone on our backdoor step in the Coral Sea area named “Oma”. This cyclone is today helping influence some rain, cloud and humidity in northern NZ but it’s only one small part of the big equation. Oma is not forecast to hit NZ or track any closer and will likely remain stuck in the same place for another seven days and won’t impact NZ’s weather beyond today.
Meanwhile a new low will quickly form overnight Saturday and across Sunday in the NZ area – this, in combination with a new big high rolling in with a colder southerly, is why we are seeing some severe weather forecasts for the weekend and latest data supports this new low spreading east from NZ quickly, meaning a shorter burst of rough weather.
WHO IS MOST EXPOSED?
There are three areas of severe weather possibilities this weekend. Heavy rain. Some snow (believe it or not!) and Gales. It’s a patchy set up which means large areas of dry and calm are mixed in with the showers, drizzle, heavier rain and increasingly stronger winds (on Sunday). It eases again on Monday quite quickly for many.
Some pockets of heavy rain are likely this weekend. Brushing Northland/The Far North, Mt Taranaki, and then parts of the lower half of the North Island and upper north east corner of the South Island. There may be a few isolated downpours that pop up here and there too.
Here’s the total rainfall accumulation map (Ie, how much rain is falling between right now and 6am this coming Monday). As you can see not everyone is in for heavy rain or big rainfall totals. Regions like Waikato, the West Coast, Southland, Otago and Nelson may all miss out on decent rainfall totals. Auckland is borderline but also looks to not get as much rain as the city and region needs (although many will be relieved this busy Saturday outdoors doesn’t look so wet!).
As this new low deepens to our east it will create a bigger air pressure gradient between that eastern low and the incoming western Tasman Sea high. This means it will become WINDY on Sunday in many regions with S to SE winds, but Saturday may well be calm for a lot.
Also, latest data increasingly supports the new low forming further east away from land – this is reducing peak winds over NZ in the forecasts for Sunday and reducing the risk of wind related damage or power cuts. WeatherWatch.co.nz is working closely this week with energy company Vector and told them some areas in NZ will have gales, maybe up to 100km/h in exposed areas, but 50km/h and below was more likely (below gale). Windiest weather will be in coastal areas from Canterbury to Hawke’s Bay and Gisborne, with Cook Strait acting as a wind tunnel and creating gales through there. Those in red and orange shaded areas below should be prepared, just in case, of isolated power cuts.
– Sunday PM shows winds peaking across the country. They don’t look as intense as previous maps showed earlier this week. Areas in red show gale force / Weathermap.co.nz.
SNOW AND COLD:
10 to 30cms of snow is possible along the Southern Alps this weekend but not to low levels. This snow will be more of a risk for those camping or tramping at higher altitudes in our national parks and mountains and may not be expecting such a cold, snowy, change in the middle of summer. It’s short lived and warms up again by Monday or Tuesday. However lower down and main centres on Sunday, like Queenstown and Dunedin for example, may only reach 12 degrees. It bounces back to the 20s next week. While no real snow is forecast in the North Island people will notice overnight lows dropping several degrees by Sunday and Monday with lower humidity … in other words, sleeping will be easier.
WeatherWatch.co.nz says people who are confused about the weather should keep up to date with our daily weather news updates and detailed 10 day hourly local forecasts. The public should also keep up to date with official MetService warnings and watches.
on 21/02/2019 10:33pm
Really nice to get balanced forecasting from you without all the hype from the media and Met Service.
on 21/02/2019 9:18pm
Thanks for adding some sensible forecasting to the hype!
Was delightful to get heavy rain for a short time just before dawn, gutters overflowed and mother Nature watered my garden which was very thirsty! The rain interrupted the crickets night songs, they are very loud this time of year!