Climatological comparison of 2011-2012 and 2012-2013 snow seasons in Central and Western Spanish Pyrenees and its relationship with the North Atlantic Oscillation (NAO)

Abstract

The 2011–2012 winter season can be considered exceptional in Spanish Central and Western Pyrenees due to the scarce precipitation and unconsolidated snowpack. However, the 2012- 2013 winter season was highlighted by the intensity and duration of snowfall episodes, specially in January and February. Snowpacks depths around 4 metres have been reported in several stations at altitudes of more than 2000 m.a.s.l. and depths over 2 metres in stations at altitudes between 1300 and 2000 m.a.s.l. Different weather and snow parameters (temperature, precipitation, snowfall, number of snow days, snowpack depth) have been taken into account to compare these two seasons. A possible influence of the North Atlantic Oscillation (NAO) teleconnection pattern in the different behaviour of the two winter seasons has been analyzed, demonstrating a clear relationship. All weather and snow data are provided from AEMET nivometeorological stations network in the Central and Western Spanish Pyrenees range, which are also presented in this work.