Thunderstorms and Lightning  

A thunderstorm is formed from a combination of moisture, rapidly rising warm air and a force capable of lifting air, such as a warm or cold front, a sea breeze or a mountain.

Severe Thunderstorm Watch: Issued when conditions are favorable for the formation of severe thunderstorms.

Severe Thunderstorm Warning: Issued when a severe thunderstorm has been sighted or indicated by weather radar.

  • A thunderstorm is classified as severe if it produces hail at least 3/4 of an inch in diameter, has winds of 58 mph or higher, or produces a tornado.
  • All thunderstorms contain lightning. The rapid heating and cooling of air near the lightning causes thunder.


Douglas County has an average of 11,000 cloud-to-ground lightning strikes annually. The Rocky Mountain Region is second to the Gulf Coast in lightning strikes nationwide.  Colorado ranks 4th for the number of lightning deaths between 1959 and 2012, at 141. 

What is Lightning

  • Lightning is an electrical discharge that results from the buildup of positive and negative charges within a thunderstorm. When the buildup becomes strong enough, lightning appears as a bolt. 
  • If you can hear thunder, you are close enough to the storm to be struck by lightning. 

Lightning Facts 

  • A bolt of lightning reaches a temperature approaching 50,000 F degrees in a split second.
  • Remember the 30/30 lightning safety rule: Go indoors if, after seeing lightning, you cannot count to 30 before hearing thunder. Stay indoors for at least 30 minutes after hearing the last clap of thunder.
  • Your chances of being struck by lightning are estimated to be 1 in 600,000.

Actions to Consider Before a Thunderstorm 

  • Assemble a disaster supply kit and make a family communication plan.
  • Secure outdoor objects, such as lawn furniture and take light objects inside to avoid loss or damage.
  • Remove dead or rotting trees and branches around your home that could fall and cause injury or damage.
  • Secure windows and doors and unplug electronic equipment before the storm arrives.

Actions to Consider During a Thunderstorm

If Outdoors:

  • If you are boating or swimming, get to land and find shelter immediately! Try to get into a building or car. If no structure is available, get to an open space and squat low to the ground as quickly as possible. 
  • If you are in the woods, find an area protected by a low clump of trees - never stand beneath a single large tree in the open. 
  • Avoid tall structures, such as towers, fences, telephone lines or power lines. 
  • Stay away from lightning rods, such as tall, isolated trees; golf clubs; tractors;fishing rods; bicycles; etc. 
  • If you feel your hair stand on end (which may indicate that lightening is about to strike you), squat low to the ground on the balls of your feet. Place hands over your ears and your head between your knees. Do not lie flat on the ground. 

If in a Vehicle:

  • Safety pull onto the shoulder of the road away from trees, turn on your emergency flashers and stay in your vehicle; avoid touching metal or other surfaces that conduct electricity.  

If Indoors:

  • Do not handle and electrical equipment or corded telephones because lightning could follow the wire. TV sets are particularly dangerous at this time.  
  • Avoid bathtubs, water faucets and sinks because metal pipes can transmit electricity.
  • Turn off air conditioners.
  • Stay away from windows and doors and stay off porches. 



If lightning strikes you or someone, call 911 for medical help as soon as possible. If the victim has stopped breathing or if his or her heart has stopped, administer CPR if you are trained. Check for burns where the lightning entered and left the body. 

Actions to consider after a thunderstorm

  • Call 911 to report life-threatening emergencies.
  • Help people who may need special assistance
  • Never drive through a flooded roadway, and only drive if necessary. 
  • Stay Away from downed power lines and report them to 911