colorectal. pertaining to or of the nature of the colon and the rectum. colorectal polyp. benign or malignant; most commonly occurs at the anorectal junction in middle-aged dogs, causing diarrhea, dyschezia and rectal bleeding.
Although favorable conditions for tornadoes in the United States can occur at any time, they are most common in spring and least common in winter. Because spring is a transitional period for the climate, there are more chances of cooler air meeting with warmer air, resulting in more thunderstorms.
There is evidence that 1000 or more additional weak tornadoes may occur each year and go completely undocumented. The Percentage of Tornado-Related Deaths 1950-2011 pie chart shows that while violent tornadoes are few in number, they cause a very high percentage of tornado-related deaths.