A cold front moving towards the country is bringing a risk of
thunderstorms for the upper North Island this afternoon.
While crossing the western Tasman Sea on Monday the front was
incredibly active with thousands of lightning strikes
detected, WeatherWatch.co.nz said.
However, as is often the case, the thunderstorms could run
out of some puff by the time they reach land, they said.
Thunderstorms were visible on satellite maps now, approaching
northern New Zealand from the west.
Current models suggest the front will move through fairly
quickly this afternoon, WeatherWatch said.
The thunderstorms have the potential to become large but may
also be fairly isolated - meaning not everyone will have
"Not all our models agree that thunderstorms are likely
today. We think Northland will be most exposed with a fairly
high risk of thunderstorms. At this stage Auckland and
Waikato have a moderate risk for a thunderstorm as the front
"As with any potential severe thunderstorms - which are
possible in isolated areas - hail, localised flash flooding
and damaging winds are possible. If you hear thunder remain
indoors until the storms have passed."
MetService spokesman Dan Corbett said they were seeing some
good lightning strikes out to the west of the country at the
"The dynamics for the line of storms is still looking rather
unstable and there's still a moderate risk of thunderstorms."
A severe thunderstorm watch is in place for Auckland.
Northland, Great Barrier Island, Coromandel, Rotorua and Bay
of Plenty, Mr Corbett said.
Strong, damaging "downburst winds" were also expected.
"And of course with severe thunderstorms you can never rule
out that small, small possibility of small little
circulations or tornadoes.
"So, an active day this afternoon across the northern parts
of the North Island."
Showers to the west of Auckland were expected to come in and
hit the central city this morning, he said.
"But the main meat of the front seems to push through for the
afternoon. So folks might get back in from lunch and then the
drive home unfortunately looks to be rather stormy, rather
windy, rather mucky with a line of thunderstorms moving
across that northern section extended down to Waikato."
The low was currently in the Tasman Sea, Mr Corbett said.
"Think of it like a two-legged octopus - the centre is the
low, one leg is the front that's bringing in that moist,
stable air generating the storms and then the other one is
the one that's sitting over Canterbury."
The front sitting over Canterbury was combining cold and
moist air, creating the possibility of snow above 400 to 500
metres for midland Canterbury, the Canterbury plains, the
high country and spreading north to Marlborough, Mr Corbett
- Brendan Manning of APNZ