 Rosecrans had his own plans to capture what he thought was the lightly defended town of Winchester and fortify and hold it as a base of operations to threaten Confederate positions at Manassas Junction.Jackson departed Winchester on January 1 with a force of about 9,000 men, under very warm spring-like weather conditions, leaving 2,000 to guard Winchester and the surrounding area.During the first night of the expedition, a severe winter storm set in, bringing snow, sleet and ice.