“A dirty thunderstorm (also, Volcanic lightning) is a weather phenomenon that occurs when lightning is produced in a volcanic plume. Dirty thunderstorms have been reported in Chile above the Chaiten Volcano, above Alaska's Mount Augustine volcano, and Iceland's Eyjafjallajökull volcano”.

Lightning bolts strike around the Puyehue-Cordon Caulle volcanic chain near southern Osorno city June 5, 2011. (Photo by Reuters/Ivan Alvarado)

Ash and steam erupti from the Puyehue-Cordon Caulle volcanic chain near Osorno city, Chile, on June 5, 2011. (Photo by Reuters/Air Force of Chile/Handout)

Locals stay in front of their home as ash and steam rise from the Puyehue-Cordon Caulle volcanic chain near Osorno city in south-central Chile June 5, 2011. (Photo by Reuters/Ivan Alvarado)

An aerial view shows ash and steam from an eruption in the Puyehue-Cordon Caulle volcanic chain near Osorno city in south-central Chile, on June 5, 2011. Picture taken through a plane window. (Photo by Reuters/Ivan Alvarado)

A cloud of ash billowing from Puyehue volcano, above southern Chile, 870 km south of Santiago, on June 5, 2011. (Photo by Alvaro Vidal/AFP)

A helicopter flies past a column of ash and steam rising from the Puyehue-Cordon Caulle volcanic chain near Osorno city in south-central Chile June 5, 2011. (Photo by Reuters/Ivan Alvarado)

A cloud of ash from Puyehue volcano rises into the sky above Osorno in southern Chile, on June 5, 2011. (Claudio Santana/AFP)

A cloud of ash pours from Puyehue volcano in southern Chile, at sunset on June 5, 2011. (Claudio Santana/AFP)

Lightning flashes amid a cloud of ash billowing from Puyehue volcano near Osorno, Chile, on June 5, 2011. (Photo by Claudio Santana/AFP)

The Iceland volcano Eyjafjallajokull erupt on April 19, 2010 sending out a plume of ash and lightning and offering a rare glimpse at the mysterious electrical phenomenon known as a “dirty thunderstorm”. (Photo by Vilhelm Gunnarsson/EPA/Nordicphotos/Jon Pall Vilhemsson/AP/Ragnar Th. Sigurdsson)