Covering period of Monday 13 – Friday 17 May – After an unusually cold week, Metservice is forecasting a return to more typically mild May temperatures as well as a rainy low pressure system coming from the Tasman Sea.
For today and tomorrow (Monday and Tuesday), we have a mix of clear and cloudy skies across the country with the slight chance of a passing shower. Patches of frost and fog are likely to return to sheltered parts of the central North Island, inland Buller, and the lower South Island tonight. Frost becomes less likely later in the week due to increased winds and overnight cloud cover, while daytime temperatures are forecast to reach the high teens in the North Island and the mid-teens in the South Island.
MetService meteorologist Dan Corrigan says, “The chances of clear skies this evening are generally looking promising for aurora seekers across the country, but the east coasts of both islands will have some cloud to contend with.”
A low pressure system currently over the Tasman Sea will arrive overnight into Wednesday morning, bringing widespread rain across the North Island and upper South Island as it moves eastwards throughout the day. Heavy Rain Watches have been issued for Tasman about and northwest of Motueka, and the eastern ranges of Bay of Plenty, lasting from Wednesday morning until Wednesday evening.
As this system moves away on Wednesday night, northerly winds give way to showery southwesterlies, but there will be plenty of sun in the gaps.
Looking ahead to Friday, a front from the south is forecast to move onto the lower South Island with strengthening northwesterly winds across the high country, and heavy rain for Fiordland and the ranges of southern Westland. Corrigan adds, “Over the week, we will be continually assessing the risk of any severe weather with Friday’s front, and will keep everyone informed about any Warnings or Watches that may be issued closer to the time as our confidence increases.”
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.
