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.
Tornadoes most frequently occur in the United States, which sees about 1,000 per year. The tornadoes usually occur in the southeastern state of Florida or in Tornado Alley, the central part of the country (Midwest) where most of the violent tornadoes occur. Canada is a distant second with about 100 per year. Twenty to thirty tornadoes per year are reported in New Zealand.