It is usually best to stay at least a quarter mile away. Sometimes a mile or more if it is large and very powerful. Generally, the further, the better.
in an underground basement
The bathroom is generally thought of the as the safest place to hide during a tornado because they normally don't have windows, and tornadoes can easily shatter the glass of them (and therefore cause injuries).
Thus Tuscaloosa-Birmingham tornado of 2011 varied in width, but at its maximum the tornado was about a mile and a half wide.
A a radar is better: it can detect a tornado at a distance. A barometer would be of no use unless the tornado came dangerously close.
The greatest distance a tornado is recorded to have traveled is 219 miles.
The safest place to be in your house during a tornado is in the basement.
The safest place during a tornado is in a basement or similar underground shelter.
The safest place to be in your house during a tornado is in the basement.
no, the safest place is a basement.
the top
The safest place to be during a tornado is in a basement or cellar.
It is safest to stay underground if you hear/see a tornado.
In a bank the safest place to be is in the vault.
in the basement
The safest thing to do is to go to an underground shelter such as a basement or cellar.
The safest place to be is in the basement of a well-built house or building.
The safest place to be in a tornado is in an underground storm cellar. You are protect from the wind an debris by the ground itself, and there is not structure above you that might collapse.