Meteorological Conditions of Extreme Avalanche Formation in Caucasian Mountains (according to Observation and Reanalyses Data)

The possibility of assessing the avalanche hazard in the North Caucasus mountains with the use of the data of modern Era-Interim, SCSR, and NCEP-NCAR reanalyses is considered. The data have been previously compared with the materials of weather stations (average seasonal values of the surface temperature and precipitation). The avalanche hazard was estimated with the use of a correlation matrix, which is based on a relationship between the avalanche hazard characteristic and the standard deviations of the seasonal values of temperature and precipitation. The synoptic processes that increase the probability of catastrophic avalanches were identified. The anomalously high avalanche hazard was shown to form at a negative anomaly of air temperature at land surface and in higher air layers at an integral moisture content of the atmosphere close to the norm.