No abstract

No abstract

No abstract

In 2015, a new automatic weather station (AWS) was installed in a high elevation site in Gredos mountains (Central System, Spain). Since then, a surprisingly high number of heavy precipitation events have been recorded (55 days with precipitation over 50 mm, and a maximum daily precipitation of 446.9 mm), making this site a hotspot in Spain in terms of annual precipitation (2177 mm year) and extreme precipitation events. The neighboring stations available in the region with longer data series, including the closest ones, already informed of wet conditions in the area, but not comparable with such anomaly behavior detected in the new station (51% higher). In this study, we present the temporal variability of detected heavy precipitation events in this mountain area, and its narrow relation with atmospheric patterns over the Iberian Peninsula. Results revealed that 65% of the events occurred during advections from West, Southwest, South and cyclonic situations. A regression analysis showed that the precipitation anomaly is mostly explained by the location windward to the Atlantic wet air masses and the elevation. However, the variance explained by the models is rather low (average R2 for all events > 50 mm is 0.21). The regression models underestimate on average a 60% intensity of rainfall events. Oppositely, the high-resolution weather forecast model AROME at 0.025° was able to point out the extraordinary character of precipitation at this site, and the underestimation of observed precipitation in the AWS was about 26%. This result strongly suggests the usefulness of weather models to improve the knowledge of climatic extremes over large areas, and to improve the design of currently available observational networks.

Recientemente se ha generado una base de datos homogénea, para estudiar la dinámica espacio-temporal del manto de nieve en el territorio español peninsular, a partir de teledetección (AVHRR-NOAA y MODIS) y modelos de balance de energía (WRF-FSM). Estas series de datos utilizadas a escala regional presentan la incertidumbre de su aplicación en pequeñas cuencas de cabecera para comprender mejor la hidro-climatología de las mismas. Asumiendo la disparidad de técnicas aplicadas, y la diversidad de variables en las que se expresan las estimaciones (extensión superficial, días con nieve, profundidad del manto y cantidad de agua equivalente), los resultados obtenidos permiten describir el comportamiento estacional del manto de nieve en la cuenca seleccionada, así como su marcada variabilidad interanual. También muestran que los datos de cubierta de nieve resultan menos útiles para el seguimiento hidrológico que las series modelizadas (WRF-FSM), que informan del espesor y de la cantidad de agua equivalente.