Great Lakes Mesoscale convective complexs or MCCs can cause damage to wide swaths of forest and shatter glass in city buildings. These storms mainly occur during the night, and the systems sometimes have small embedded tornadoes, but more often straight-line winds accompanied by intense lightning. Historically, the Great Lakes, in addition to their lake ecology, were surrounded by various forest ecoregions (except in a relatively small area of southeast Lake Michigan where savanna or prairie occasionally intruded). Logging, urbanization, and agriculture uses have changed that relationship. In the early 21st century, Lake Superior's shores are 91% forested, Lake Huron 68%, Lake Ontario
Naval Station Great Lakes opened. The policy of segregation led to small service school classes with only four or five students in a class. By 1944 Great Lakes began to integrate training and all training was integrated by mid-1945. The Golden Thirteen were commissioned in March 1944 after training at Great Lakes. Four million served on active duty in the Navy during World War II. Over one million sailors were trained at Great Lakes. In 1948, a boot camp for WAVES (female recruits) opened at Great Lakes, first graduating 5 October 1948. In 1951, female recruit training left Great Lakes for United States Naval