Updated 31st January 2025:
Mangawhai and the surrounding areas over the years has had its fair share of severe weather.
Again they have experienced in what is likely to have been a tornado touching down in the early hours of Sunday morning. With further investigation on radar imagery, there seems to be evidence of a phenomena known as a splitting storm that occurred over Bream Bay, Northland. The 1st part of the splitting storm headed south-east into the gulf with the 2nd part heading towards Mangawhai. Both storm cells have likely spawn tornados. Here is how the events unfolded.
On early Saturday 25th January a Tasman low matured to the west of the North Island, spawning a north-west cloud band and multiple fronts heading eastward towards the upper North Island.
A key ingredient in the recipe for a severe weather outbreak is the behaviour of jet streams and this atmospheric set up had the interaction of the subtropical and polar jet streams.
By near night fall, lightning active multicellular thunderstorm clusters had developed 100 km NW of Northland.
At 9:10pm MetService issued it's severe watches or warnings for Sunday. No watches or warnings were put in place for the upper North Island and a low risk for severe thunderstorms in their outlook issued at 8:33pm.
At 1:52am a multicellular thunderstorm cluster ahead of an occluded front was heading south-east over lower Northland towards Bream bay.
By 2:45am the thunderstorm had split in 2 with 1 cell heading southward and the other cell heading south-east. Potentially is was a phenomena called a splitting storm
At 2:52am a hook echo appeared on the radar around the Mangawhai suggesting rotation within a mesocyclone and a tornado could be possible in the area. At the same time the storm over Bream bay also started to develop a hook echo signature.
On the ground resident Shannon Poynter took video of the likely mesocyclone over the top of Mangawhai with constant strobe lightning being generated by the rogue thunderstorm cell.
The radar image at 3.30am shows the 1st storm that developed over Bream Bay now having a complete hook echo off the coast near Leigh. This would have very likely been a new tornado over water.
Daylight revealed extensive damage to property and trees with 2 residents unfortunately seriously injured.
Wind damage on multiple houses in a likely Mangawhai EF1 tornado
More wind damage on another house in a likely Mangawhai EF1 tornado.
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