MADRID (Reuters) – Army units were mobilised to help about 600 drivers who were stuck on a motorway in heavy snow as Storm Juan blanketed many parts of Spain, authorities said on Friday. Snowfalls left motorists stranded for hours on the N-122 road between Soria and Agreda in northern Spain so authorites said they had dispatched troops from a base in Zaragoza to help move the drivers. Miguel Ángel Clavero, of the civil protection force, said on Friday that in Aragon in eastern Spain a number of roads were left unpassable by the snowfall and Zaragoza airport was closed. Temperatures plunged to …