Mountain accidents associated with winter northern flows in the Mediterranean Pyrenees

The Mediterranean Pyrenees, at the eastern end of the range, is a very popular area. Its highest peak is at 2900 m a.s.l. and there are numerous peaks above 2000 m, with rounded relief and sparse vegetation on the latter height. One of its significant winter climatic features is the sudden entrance of cold air with violent northern winds, drop in temperatures and very low wind chill values. Such advections are established after the passage of a snowy cold front and, consequently, there is abundant transport of both new and existing snow that reduces horizontal visibility. The post-frontal conditions at high altitudes represent a serious threat to humans. The review done shows that the hikers immersed in an environment of low visibility, strong winds and very low temperatures can quickly become disoriented, suffer frostbite and hypothermia and slip on the ice. The characterization of a series of accidents occurred in this geographical area, identified in the press, shows in this paper that the phenomena associated with northern winter advections is an element of danger to be considered in the evaluation of natural hazards in that area. In addition, the multiple character of many of the events suggests that there is high vulnerability to such dangers. The climatological analysis presented suggests that such weather conditions are not uncommon in the winter, although the most serious accidents have been registered under especially strong and cold flows. The conclusions recommend that the weather conditions described, locally called torb, should be known by the visitors to these mountains in the winter, and its appearance should be announced in weather reports, which in turn must be sufficiently disseminated in the areas of greater abundance of tourists and hikers.