The role of vertical wind shear in the great pyrocumulus of Costa del Sol (Málaga, Spain) on 30 August 2012

Abstract

On August 30th, 2012 a disastrous fire was recorded on the Costa del Sol, Spain (1) in a situation of northerly flow at low levels called "Terral". This terral creates an environment of high temperatures, low humidity and strong winds, very favorable to the forest fires spreading to the coast very quickly. During the fire started on August 30th, the NW flow at low levels changed abruptly to a east maritime wind (2) with a behavior of gravity wind and a sudden wind entrance from east (3), and very serious consequences: a sudden change in the speed and the direction of propagation, and in magnitude of the fire (4), which greatly hindered its control. The sharp increase in vertical wind shear that caused the outbreak of the density current (5 and 6) is proposed as an explanation for the extreme fire characteristics (duration, propagation speed and intensity).