Myth: Tornadoes don't cross rivers.
Although some landforms may influence the distribution of tornadoes, rivers do not have any clear effect on them. The great tri-state tornado of 1925 crossed both the Mississippi and the Wabash rivers.
Myth: Open windows in your house to equalize pressure.
Do not do this. Your house will not “explode” due to a tornado passing over it and taking time to open windows merely reduces your ability to seek safe shelter in time.
Myth: Get to the southwest corner of the building for safety.
The safest place in a building is in a small, reinforced room (such as a bathroom or closet) near the center of the building, on the lowest floor (preferably below ground). Safer yet, of course, is a shelter specifically designed for tornado safety.
Myth: Tornadoes skip.
Sometimes, the damage path of a tornado will result in demolition of several buildings, followed by several lightly damaged, followed by several more demolished. This gives the impression that the tornado “skipped” over the less-damaged structures. There are several explanations for this. One is that the surviving buildings were better-constructed. Also a possibility is that the orientation of the buildings resulted in varying degrees of vulnerability.
SOURCE: NATIONAL WEATHER SERVICE