22/02/2023 – Covering period of Wednesday 22 – Saturday 25 February
MetService is forecasting rain to continue to move up the country in the next 24 hours. As it does, it will shift from its current focus to the North Island. The majority of the North Island will get some rain before the weekend, with eastern regions bearing the brunt, but the exact amounts expected span a broad range at this stage.
MetService meteorologist Angus Hines says, “When forecasting for a potentially severe weather event, MetService analyses an array of incoming information, much of which comes from the most cutting-edge weather prediction centres in the world.”
“When all this information closely aligns, it gives us high confidence in the forecast, and allows to provide fairly narrow ranges for expected rainfall values.” continues Hines, “However, today, these information sources are not aligned with respect to how much rain is going to fall across the eastern North Island in the coming days.”
This results in a large range of possible outcomes, and reflects the current state of the atmosphere, being very sensitive to new weather developments.
Looking at the comparison below, this shows three of the possible outcomes for how much rain may fall in the coming days.
“It’s times like this that it is tricky to pin down rainfall amounts in our forecasts and warnings. One thing is for sure, any rain across recently flooded areas is unwanted and unwelcome, so even the less severe end of the range might result in further issues like slips and road closures in these hard-hit areas.” says Hines.
Currently, a Severe Weather Watch is in force for eastern regions, and its likely that some places will be elevated to Orange Severe Weather Warnings in the next 12-24 hours, especially if confidence in the expected rainfall increases. You can check out the current Severe Weather information here at www.metservice.com and Local information will be provided by your Civil Defence Emergency Management Group. Where possible, people should try to prepare themselves by clearing their drains, and topping up their stores of food, water, and medicine.
Looking to the Tropics
While the tropical waters north of New Zealand are quiet for now, things are not expected to stay this way. Late February and early March are the peak of the tropical cyclone season for the Southern Hemisphere.
“Historically, this is the most likely time of year for tropical cyclones to form, with a greater than 50% chance of a cyclone forming or persisting over any 7-day period,” informed Hines.
Next week, activity in the Tropics is expected to amplify, with a risk of a tropical cyclone developing. If a tropical cyclone does form, there is a chance it could follow a south or southeastward trajectory towards New Zealand late in the week. It’s important to note this is only one possibility, there are several other paths which a cyclone could follow, which would steer it away from the country.
Every day MetService has designated tropical forecasters, who are assessing the risk of any tropical systems impacting the country. We get more information each day, and will keep you up to date with what you need to know.
Understanding our Severe Weather Watches and Warnings
Outlooks are about looking ahead:
To provide advanced information on possible future Watches and/or Warnings
Recommendation: Plan
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
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
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!
