Thunderstorms are bearing down on the North Island likely to bring large hail and damaging winds to go with the light show.
At 09:30 pm, MetService weather radar detected severe thunderstorms near Manawatu.
"These severe thunderstorms are moving towards the east, and are expected to lie near Manawatu at 10.00 pm and near Palmerston North and the Manawatu Gorge at 10.30pm.
"Very strong wind gusts can break branches from trees, damage roofing, and make driving hazardous especially for high-sided vehicles and motorcycles," MetService said.
A severe thunderstorm watch remained in place for Taranaki, Wanganui, Manawatu and Kapiti-Horowhenua.
Severe Thunderstorm Warning issued on two storms moving onshore Manawatu with frequent lightning, heavy rain, large hail and strong winds. Risk period 10:00-10:30pm. ^JC. https://t.co/nDGu5wiiVW— MetService (@MetService) May 24, 2018
It came as overnight temperatures were likely to drop to as low as -4C in the South Island and as high 12C in the Auckland and Northland regions.
The weekend will bring more cold nights as unsettled wintry weather including but not limited to thunderstorms, snow, hail, rain and wind is forecast across the country.
The cold snap gripping the nation wasn't going anywhere soon, MetService meteorologist Tui McInnes said.
A number of fronts would push over the country from the south through the weekend with each front bringing shower and rain and cold overnight temperatures.
That spelled rain hail and wind for the North Island and snow and freezing temperatures for the South Island.
McInnes said a front moving up the country today will bring wet and windy weather to exposed places in the North Island overnight and into tomorrow.
In addition, large swells from the southwest were also expected for western coasts.
A low pressure system over the North Island is expected to move away to the east on Saturday, followed by strong cold southwesterlies over much of the country.
Continuing the cold weather talk, tonight's forecast minimum temperatures are cold! Get the electric blanket on, turn on the heaters, light the fireplace!— MetService (@MetService) May 24, 2018
Tips to help stay warm
EECA Energywise technical expert Christian Hoerning has provided some tips to keep warm this winter:
Well installed insulation that helps keep the heat in during winter is the priority. Insulation makes your house easier to heat properly, and more comfortable and healthy to live in. Colder houses place greater stress on older people, babies and the sick and are more likely to have mould that causes respiratory symptoms.
Insulation works by slowing heat loss from your house, making it easier to warm. If your house is not insulated, good quality, well-installed underfloor and ceiling insulation could halve your house's heat loss.
If you have insulation, it's worth checking to see if it is up to scratch. Old insulation may have settled, become damp or have gaps and no longer perform well. Sometimes insulation also gets moved around when people are doing work in the roof space or under the house.
Government programme Warmer Kiwi Homes offers grants from July 1 covering two thirds of the cost of ceiling and underfloor insulation, as well as ground vapour barriers. Additional contributions from community organisations will be sought to make the retrofits as low cost as possible.
Grants covering two thirds of the cost of heating appliances will be available from July 2019.
For larger rooms you want to heat regularly like a living room, it's worth paying a bit more upfront for a fixed heater with lower running costs and more heat output than an electric heater. This could be a modern wood or wood-pellet burner, an energy-efficient heat pump, or a four-star flued gas heater. Electric heaters may be enough for smaller rooms and rooms you only heat occasionally, like bedrooms - they're cheap to buy but more expensive to run.
Lined floor-length curtains can reduce window heat loss significantly. To work effectively, the curtains need to create a reasonably good seal to trap the air in the gap between the curtain and the window – if they are installed with gaps around their edges, air can circulate freely and won't insulate much.
There are curtain banks in many areas that offer free curtains to lower-income households.
Ventilation is important, but getting it right is a balancing act: if there is not enough ventilation, air quality won't be maintained and moist air will not be able to escape. However, too much ventilation means a draughty, cold house.
Start with moisture hot spots: kitchens, laundries and bathrooms. Install extractor fans that vent outside (not into your roof cavity) to take away moist air. If you can't install extractor fans, open the windows when you've been cooking, showering or drying clothes to let moisture escape that way.
Follow this up with some simple draught stopping. Fill any gaps in floor boards and around window and door frames. Install weather stripping on the inside of window and door frames.
Air the house
Finally, make sure your house gets a regular airing – a quick blast of fresh air through the whole house a few times a day should be enough. Home ventilation systems are a convenient alternative but can be expensive – just airing the house regularly yourself should achieve all the ventilation you need.
Low-cost tips for saving energy in winter
• Shut your curtains at dusk to keep the heat in.
• Use window insulation film. This is a cheap, easy way to insulate windows, although it's not as durable as actual double glazing. Used in conjunction with well-fitted, thermal backed curtains, it is a good, low-cost window insulation option.
• Only heat the room you're using. Keep the door closed and use door snakes to keep the heat in.
• If you have a heat pump, use its timer and thermostat and clean the filter regularly. No matter how great the specs, a heat pump cannot perform efficiently if you don't look after it or leave it on all the time at full bore.
• If you have a fireplace that isn't used, prevent draughts by filling a large plastic bag with crunched up newspaper (make sure people know they can't light the fire).
• Replace standard light bulbs with LED bulbs.
• Install a cylinder wrap around your electric hot water tank and insulate the first few metres of hot water pipe.
• Install an efficient shower head.
• Wash your clothes in cold water.