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.
When and where do tornadoes occur? Most tornadoes occur east of the Rocky Mountains in a region known as Tornado Alley. The vast majorities of tornadoes occur in the deep south as well as the broad, relatively flat basin between the Rockies and the Appalachians, however no state is immune.