Arthur & Grand Valley escape disaster as powerful tornado narrowly avoids towns
This tornado was incredibly photogenic; it was reported, photographed and filmed by a number of CANWARN spotters and storm chasers including this author, Travis Farncombe, as well as Dave Patrick and David Chapman. It travelled along Highway 109 on a path that was 4.5km long and 100m wide, developing just east of Arthur and dissipating just west of Grand Valley. The towns narrowly escaped disaster as it passed between them without inflicting any major damage.
It formed as a swirl of dust and debris beneath a rapidly rotating wall cloud with low-hanging fingers, then lifted briefly before coming back to the ground to stay. It condensed downward, narrow and dart-like, then became more serpentine as it undulated and headed to the east.
During its mature stage, the tornado intensified, becoming a drill bit with intense, rapid rotation at its base as it tore a tree from the ground and lofted it hundreds of metres into the air. As the tornado neared the end of its life, it became a tapered cone with a plume of dusty debris at its base, then roped out before reaching the village of Grand Valley. It had been on the ground for close to twenty minutes.
The tornado received a low rating since it spend most of its time over open fields, damaging only a few trees and levelling a swath of corn. However, it is likely that this tornado was capable of much stronger EF2 or EF3 damage had it impacted either of the towns that tracked between.
This was one of five tornadoes that touched down on August 7, 2013. The others:
