Tristan da Cunha News of Storms and the Community's Response
News of storms and other notable weather phenomena that have hit Tristan, including the damage caused and subsequent repairs.

Twister hits Potato Patches
Report and photos from Shirley Squibb

Mid-morning on Wednesday 5th August 2015, a twister was spotted at sea, off the Potato Patches, by the agricultural team working there. It quickly made it's way to shore lifting the water high in the air as it travelled across the sea. Hitting land it moved through the patches towards the Hill Piece lifting roofs from potato seed huts and camping huts. The debris could be see flying up to an estimated 90m high before being strewn over the fields, the twister then disappeared into the mountain.

Above: damaged camping hut roof
Right: broken roofing piercing the pasture.

Above: The remains of a potato seed hut
Right: A twisted up drum and wood plank spearing the ground

Editor's Note
'Twisters' that occur on Tristan are usually products of winter storms where low pressure systems are uplifted by the Tristan cliffs and may then develop into eddies, often known locally as a 'Willy'.

The name 'Willy' is also a common colloquial name for a cyclone and tropical storms, known as hurricanes in the Atlantic Ocean are called a 'Willy-Willy' off Northern Australia. In Aboriginal myths, the willy-willy represents spirit forms. Children were warned of a spirit that would emerge from the spinning vortex if they behaved badly. In Indigenous America, the Navajo believed they were ghosts or spirits of the dead called Chiindii.

Technically this August twister was a 'Waterspout' as it approached over the sea (as it's extreme low pressure 'sucked' up sea water) and a 'Tornado' as it continued over the land, its violent wind dismantling those man-made structures in its path.

Although usually associated with summer conditions, especially in the USA, tornados also effect many temperate countries, including the UK and the Netherlands, which has the highest incidence of tornados per area of any country in the world. Nevertheless temperate tornadoes are far less strong than those occurring the the southern USA or Bangladesh where high summer temperatures produce a much stronger vortex and cause fatalities where they effect urban areas.

One very local tornado or willy occurred on 16th September 1982. OAPs Freddy and Alice Green were, as usual, going to milk their cow which was in the fence behind the village. Walking together, Alice was lifted off the ground by a sudden vortex and thrown against a lava block wall. Freddy was not only unharmed, but did not feel the very local wind, even though they were walking together! Alice was treated in Camogli Hospital where she remained for a few days, but made a full recovery within a month.

May Storm
Photos of a storm battering Calshot Harbour on Saturday 24th May 2014
from Tina Glass

 

 

   
   

More images taken on 24th May 2014 (above)
and on 26th May (left)
by Drew Campbell of the storm
attacking Calshot Harbour

Drew reports that on Friday 25th May
a combined PWD / Factory team
removed barges from the harbour using the crawler crane
and also sited the smaller raft up higher off the quayside.
There was also a big clear-up of materials and equipment
both then and on Saturday morning
to prepare for the forecast storm to minimalise any damage.

 

August Hail Storm

Dawn Repetto took this vivid photo
of a hail storm experienced in the Tristan da Cunha Settlement on 27th August 2013.

Frost is unknown in the Tristan village but snow falls on the mountain and can often be seen in winter and spring on the higher slopes of the fringing cliffs, especially above the Potato Patches.

Hail is rain which is thrust upwards into colder areas of the atmosphere where it freezes. The strong uplift given to air masses by the Tristan mountain can cause hail to form as it did on this wild August day.