Weather Watch: Thunderbolts and lightning, very very frightening!

Lightning strikes the ground after storms outside Christchurch today. Photo / John McCombe

Thunder and lightning last night lit up the skies from Auckland to Invercargill overnight as unsettled weather conditions develop over New Zealand.  Most affected was the vulnerable and exposed region of Taranaki where reports came in at the peak of the storm (around 8pm last night) of almost non-stop lightning.  Reports also came in to WeatherWatch.co.nz of lightning around Hutt Valley and Christchurch – and it was clear from our Lightning Tracker that lightning was widespread across the country…and still is this morning.
 
At the peak of the activity we clocked up around 430 strikes per hour.  That's not especially high but the thunderstorms seemed more concentrated in each area rather than widely scattered.
 
The unstable weather also produced a tornado or sudden downdraft which lifted roofs in the Taranaki town of Opunake.  This area is no stranger to thunderstorms and tornadoes.  In the North Island Taranaki is most exposed to this violent weather….when you look at a map you can clearly see why.   Taranaki juts out into the Tasman Sea and is surrounded by water to the north, west and south.  It is highly exposed.  It's this exposure that allows thunderstorms and heavy showers to move in from the Tasman Sea uninterrupted by land.  The storms come in offshore at their peak and slam into Taranaki.
 
West Auckland is also exposed to these thunderstorms as is South Auckland.   However it's the South Island's West Coast that is New Zealand's thunderstorm capital.
 
The unstable, unsettled, weather is going to remain for a few days yet…perhaps a few weeks yet.   A very deep low is about to form off the Southland coast and that's going to fuel strong winds and rain bands across New Zealand tomorrow and Friday.  Expect more thunderstorms in the west, gales in the east and heavy rain in the south and west…and possibly north.  
 
On Sunday a ridge of high pressure should bring a brief period of settled weather to many places however it will be very short lived with computer models already predicting another Tasman Sea low early next week.   This should make for a wet end to July and I'm thinking August may be more unsettled and dramatic than last year.
 
As of 6am our Invercargill Weather Watch reporter Malcolm Gayfer said thunderstorms had been raging for at least an hour.  His exact words were "haven't seen it like this in yonks!".  Sums it up nicely.  What I haven't seen in 'yonks' is such widespread thunder and lightning…from Auckland to Taranaki across Wanganui and down to Wellington, then down to Christchurch and now moving into Invercargill and Southland.  Unusual to see lightning on both the east coast and west coast in winter.
 
Looks like an interesting few days ahead.
 
Useful links:
-          Follow me on Twitter
-          Lightning Tracker
-          News story and reader comments on overnight thunderstorms