Understanding the Weather [ 433 



cloud to another; very few come down to earth, and only when 

 the negative charges in a cloud are attracted to positive charges 

 on the ground. 



Probably the safest place to be is indoors when there is a storm 

 in your neighborhood. If you happen to be outdoors and without 

 available shelter, be sure to avoid high ground, trees standing 

 alone, the edges of woods, and wire fences. In case the lightning 

 is unusually severe and directly overhead, your safest course is to 

 lie or sit in a ditch. 



How MANY MILES BETWEEN You AND LIGHTNING? 



Most children enjoy being able to reckon how far lightning 

 is from them; and knowing how to do this is especially comforting 

 to the nervous child who imagines that every flash is directly over 

 his head. The calculation is based on the lapse of time between 

 a flash and the moment the resulting thunder is heard. So quickly 

 does light travel that the lightning is seen almost the instant it 

 flashes. Therefore, if you count the number of seconds that elapse 

 between the flash and the thunder, you know, roughly, the distance 

 between you and the storm center. 



You can train yourself to count seconds without a timepiece 

 by repeating some such phrase as "storm in the sky," which takes 

 a second to say. A lapse of fifty seconds means the lightning is 

 about ten miles away (a mile distant for each five seconds) . You 

 cannot hear thunder from a greater distance than ten miles, except 

 under unusually favorable circumstances. 



THUNDERSTORMS 



You have probably noticed that there are different kinds of 

 thunderstorms and that they have different effects on the atmo- 

 sphere. Moreover contrary to popular belief they may even oc- 

 cur in winter. The two kinds that most often visit us in summer 

 are the local or "heat" thunderstorm and the "cold front" type. 



Heat Thunderstorms: The heat thunderstorm is generally a small- 

 scale affair leaving the atmosphere as oppressive as before it broke. 

 This kind is most common in the late afternoon or early evening 



