Covering period of Thursday 14 – Sunday 17 March
With a forecast of rain, southerly winds, and snow for this weekend, the advice from MetService is to layer up, especially if you are spending time outdoors.
The blast of cold air reaches the far south of Aotearoa New Zealand Thursday afternoon, with the coldest temperatures being felt in the South Island on Friday. Canterbury, Otago, and Southland can expect a maximum temperature of 15°C or less on Friday, about six degrees below the average for this time of year, with the remainder of the South Island only reaching the high teens.
A Road Snowfall Warning has been issued for Porters Pass (State Highway 73) as the cold air mixes with rainfall over alpine areas; snow showers are expected from about 800 metres upwards.
MetService Meteorologist Clare O’Connor expands: “The real chill for the South Island will be felt overnight into Saturday morning, as clear skies following the passage of the cooler air will mean no clouds to bring an insulating effect. Anyone living or travelling through inland South Island areas should plan for below zero temperatures overnight, although all of the South Island will be under 10°C in the early hours of the morning.”
While the North Island will not begin to feel the brunt of the cold air until late Friday, a wide band of rain lies over central and western regions on Thursday and into Friday afternoon. The southerly winds and showers arrive about the lower North Island Friday evening and continue pushing northwards overnight into Saturday, eventually clearing off the north of the North Island Saturday morning.
Despite the wet beginning to the weekend, Saturday and Sunday are expected to be relatively settled and sunny during the day. The chill in the air will remain through the weekend, making this likely to be the coldest weekend of the year so far. The Auckland Region may even see its first daily maximum temperature below 20°C since early December last year. With the autumn equinox occurring next week, more crisp mornings are no doubt on the way.
Understanding MetService Severe Weather Warning System
Severe Thunderstorm Warnings (Localised Red Warning) – take cover now:
This warning is a red warning for a localised area.
When extremely severe weather is occurring or will do within the hour.
Severe thunderstorms have the ability to have significant impacts for an area indicated in the warning.
In the event of a Severe Thunderstorm Red Warning: Act now!
Red Warnings are about taking immediate action:
When extremely severe weather is imminent or is occurring
Issued when an event is expected to be among the worst that we get – it will have significant impact and it is possible that a lot of people will be affected
In the event of a Red Warning: Act now!
Orange Warnings are about taking action:
When severe weather is imminent or is occurring
Typically issued 1 – 3 days in advance of potential severe weather
In the event of an Orange Warning: Take action.
Thunderstorm Watch means thunderstorms are possible, be alert and consider action
Show the area that thunderstorms are most likely to occur during the validity period.
Although thunderstorms are often localised, the whole area is on watch as it is difficult to know exactly where the severe thunderstorm will occur within the mapped area.
During a thunderstorm Watch: Stay alert and take action if necessary.
Watches are about being alert:
When severe weather is possible, but not sufficiently imminent or certain for a warning to be issued
Typically issued 1 – 3 days in advance of potential severe weather.
During a Watch: Stay alert
Outlooks are about looking ahead:
To provide advanced information on possible future Watches and/or Warnings
Issued routinely once or twice a day
Recommendation: Plan.
