THUNDERSTORM T0080 (Severe Linear MCS)
Date: Thursday 12th May 2011
Time: 17:00-23:00 BST
Location: Box, OK, Sallisaw OK, Lee Creek AK, Fort Smith AK, USA.
Path: Overhead

Synoptics: Destabilised Tropical plume ahead of advancing tough, then thundery surface front
Duration: 5 hours (chase)
Type: Multicell
Average lightning type: CG / Anvil Crawlers
Footage Quality: Full HD / DSLR

 

On the last day of our self-catered stormchase holiday in the US, we ran out of supercells (2 weeks of high pressure - there weren't many anyway) so we went full-on into a severe MCS (Mesoscale Convective System) to see what spectacles that would give.

The storm started off as an ambient group of elevated cells erupting out of Altocumulus Castellanus fields ahead of a trough. A couple of hours later they upscaled and very quickly went surface-based with CAPE values around 1500-2000J/kg. We had 3cm hail, whilst Sallisaw town itself reported golf-balls, extreme downdraughts, lots of lightning, big rainbows and adventurous rural roads at Lee Creek were plenty to get our British adrenaline going. The day finished off with a lovely display of anvil-crawlers, then the sneaky cold front we didn't know was coming, followed by another C-G barrage before retiring in Fort Smith.