Change the number on the weather slider to make it rain (2), snow (3) or hail (4). 5 is all weather mode and 1 is clear. Change the amount of people slider to add or take away people. Press L to make a lightning storm and T to make a tornado. Press the up arrow to get rid of the tornado and the down arrow to get rid of the lightning. Only pressing the green flag gets rid of the tornado and the lightning. Lightning, tornados and hail have a chance of killing the people.