MADRID—Heavy snowfall brought by Storm Filomena put parts of Spain including the capital Madrid on high alert on Friday, causing traffic congestion and forcing authorities in some regions to deploy the military to clear access to villages. With up to nearly 8 inches of snow forecast in 24 hours and temperatures expected to hover around zero centigrade for much of the day, the south of the Madrid region, including the capital, is on its highest level of alert for the first time since the system was created in 2007. Such events are rare in the region and tend to be disruptive to daily life and mobility, coming at a time when people are returning home after Christmas and New Year holidays. This year, however, there is less traffic than usual due to restrictions to curb the coronavirus pandemic. Large parks in Madrid, including the famous Retiro next to the Prado …