Covering period of Thursday 11 – Sunday 14 January – MetService is forecasting high temperatures to endure through the weekend, with warm northwesterlies developing again on Saturday – a repeat of the current set up over the South Island/Te Waipounamu, while a ridge dominates the situation in the North Island/Te Ika-a-Māui.
A warm, moist northwesterly flow is delivering rain to the west and the south of the South Island today (Thursday), resulting in a Heavy Rain Watch for southern Westland until Thursday evening. The flow dries out and heats up as it travels over the Southern Alps in a classic foehn wind scenario, pushing up the mercury as it reaches eastern areas – Christchurch reached 31°C early Thursday afternoon as the hot air touched down in the Garden City.
Up north, the settled and mostly sunny days continue into Friday for the North Island/Te Ika-a-Māui: temperatures about average; showers mostly isolated and inland; morning clouds giving way to blue skies. While northwesterly winds pick up on Thursday evening for the lower North Island, they drop out again Friday morning.
MetService Meteorologist Clare O’Connor expands: “A weak cold front travels up the South Island overnight into Friday bringing about a change to easterly winds on Friday morning and low cloud pushing onto the east coast with the return of ridge conditions. This wind change will also be felt over in the west, with the dying out of the northerly winds and the sun poking through by afternoon there. North Islanders will be mostly unaffected, aside from cloudier conditions to start about the Kapiti Coast and Wellington.”
The ridge over the South Island is short-lived, and another warm, moist northwesterly flow develops Saturday morning and travels northwards up the country. MetService’s Severe Weather Outlook signals heavy rain affecting the south and west of the South Island again from Saturday afternoon; any necessary Severe Weather Watches or Warnings will be issued closer to the time. Temperatures are forecast to rise once more in the east of the South Island, but the east of the North Island will feel it too this time: models are currently indicating that Hastings could reach 33°C on Sunday.
MetService advises anyone out and about in the sunshine over the next few days to remain sun smart: slip, slop, slap, and wrap, and make sure you have sufficient fluids to keep you hydrated. Heat alerts will be issued for locations that are reaching their highest temperatures – keep up with your local forecast to make sure you are the most prepared you can be for the day.
But cooler air is on the horizon: “A fresh southwesterly change early Monday will be in sharp contrast to the hot weather of the weekend – maximum temperatures are forecast to barely reach the high teens early next week, in some places this is even lower than recent overnight temperatures, which might be appreciated by anyone who has been struggling to sleep this last week.” O’Connor says.
For media enquiries or to arrange an interview with one of our meteorologists please call 04 4700 848 or email metcomms@metservice.com
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.
