National Weather Service United States Department of Commerce

Be A Force Of Nature!Summer storm season will soon be here.  Severe thunderstorms with large hail, damaging straight line winds, and tornadoes and flash floods can develop suddenly.  People need to respond quickly when warnings are issued to protect themselves.  The information on this page can help you prepare for severe storms and flash floods, so you can Be a Force of Nature!


Have an Escape Route.  Isolated thunderstorms with intense heavy rain can lead to dangerous flash floods, especially in the Black Hills.  Larger storm systems can cause widespread flooding that swells streams and rivers, covering roads and highways. You need to be react quickly if your home is threatened by rising water.

  • Learn if your home or workplace is in or near a floodplain by using the FEMA Flood Map Service Center.
  • Know the steams you cross often so you know if you’re approaching a flooded area.  Find the best way to get to higher ground without having to cross a stream when evacuation orders are issued.
  • When camping, choose campsites away from steams.  Do not camp where your only exit crosses a stream.
  • Watch for signs of intense storms upstream of your location which can cause flash flooding downstream. If you see water starting to rise, leave immediately—don’t wait for a warning or evacuation notice.
  • If you do approach water over a road, turn around. Do not drive into the water—the road or bridge may be already washed out. Most vehicles can be swept away by only one to two feet of moving water.

Make a Communications Plan.  Your family members may not be together or at home during an emergency.  Making a communications plan will enable you to contact each other and may help you reunite sooner.  Basic steps in a plan includes making sure everyone knows where to go, how to contact each other, and meeting places if you can’t get back home.  A guide for creating a plan is at

The American Red Cross’ “Safe and Well” site ( allows you to let your family and friends know you’re safe and search for relatives and friends affected by disasters. 

Find a shelter.

          At home:

          • Go to the basement or small interior room on the ground floor; such as a closet, bathroom, or hallway.

          • Get under the stairwell or a sturdy table and cover yourself with pillows or blankets.

          • Avoid the corners and exterior walls of the house.

          • Stay away from windows.  Do not open the windows; it does not reduce damage to the structure.

          • Mobile home residents should go to a shelter well before the storm reaches them.  If there isn’t time or a shelter available; lie flat in a ditch, ravine, or culvert away from the home and cover your head.

          In public facilities or large buildings:

          • Go to the designated shelter, usually a room on the lowest level.  Use the stairs, not the elevator.

          • Stay away from large windows and skylights.

          • Do not remain in large rooms with high, unsupported roofs; such as gymnasiums, halls, warehouses, or church sanctuaries.

          If caught outside:

          • Leave your vehicle.  Lie flat in a low area like a ditch or culvert and cover your head.  Choose a location clear of trees that may fall on you and watch for rising water from heavy rain.

          • Do not take shelter under a highway overpass.  You can be injured when strong winds and debris are channeled through the small opening under the bridge.

          • Do not try to drive away from a tornado in a city, heavy traffic, or mountainous areas.

Get the warning. Alerts for dangerous storms and other incidents are available from many sources, so you should be able to receive them in any location.  Most of these methods are intended to get people’s attention that a serious event is occurring, which requires you to get instructions on the appropriate actions to take.  You should know what systems you can receive and how to get the details about events.

Warning sirens are used by many communities for life-threatening situations—not just tornadoes.  They are intended to notify people outdoors to get inside, so you may not be able to hear them indoors, especially in office buildings or stores. 

Local radio, television, and cable systems broadcast warnings through the Emergency Alert System.  Warnings are not available on satellite TV channels unless you are watching a local station.

Cell phones can receive official messages through Wireless Emergency Alerts.  This is a free service for which you do not have to sign up or download.  Alerts are broadcast from cell towers in the vicinity of an emergency, so you will receive them for your current location.  Find out if your phone is WEA-capable at  You can also download other notification apps.  Check whether they will provide alerts for the area you specify or your current location.

NOAA Weather Radio is a network of radio stations operated by the National Weather Service.  Receivers are activated when warnings are issued, so it’s like having a personal siren in your home or office.  The receivers have battery backup, ensuring you will receive the warnings even when the power is out.  The warnings are repeated every one to two minutes and bulletins updating the storm’s current location and track are automatically included in the program.  NOAA Weather Radio stations serving South Dakota are listed at

National Weather Service web sites and provide maps of active alerts and warning details such as expected hazards, impacts, storm tracks, and locations affected.

Build a Kit.  Even in the summer, storms can cause power outages that last a day or two, so you still need to have emergency supplies at home.  Essential items such as flashlights and batteries, a battery-powered radio, first aid kit, non-perishable food, and water for drinking and other uses should be ready when needed.  Have a corded telephone to make and receive phone calls if the power is out at your residence or nearby cell tower.

If you live in a flood prone area, you also need to assemble a kit in a plastic tote or rolling suitcase to take with you if you need to evacuate. This kit should include cash, important documents, clothing, prescription medication and medical supplies, baby items, and pet supplies.

A list with more items to include in your kit is available at

Know the terms.  The National Weather Service uses the following terms in their hazardous weather bulletins:

A Watch means severe thunderstorms, tornadoes, or flash floods are possible.

 A Severe Thunderstorm Warning means a thunderstorm with wind gusts of 58 mph or higher or hail at least one inch in diameter is occurring.  The definition of a severe thunderstorm does not include lightning; ALL thunderstorms contain lightning and should be considered dangerous.

A Tornado Warning means a tornado has been sighted or indicated by radar. Take shelter immediately!

          For additional information, contact your county emergency management office or visit the National Weather Service web site, Department of Homeland Security or the American Red Cross