Severe Weather Filler

Tornadoes

• Don't leave home or other substantial shelter
  • Overcrowded roads, especially in urban areas; impassable ones in rural areas (May 2013 Oklahoma City tornadoes -- lots of people tried escaping via freeways, which turned into parking lots and left them sitting ducks)
  • If there's one tornado, there could be others that appear unexpectedly (outbreaks are common)
  • A tornado's path can be highly erratic, so driving in what appears to be a safe direction may not be safe at all (that's what killed Tim Samaras in Oklahoma in 2013, and nearly killed Mike Bettes of the Weather Channel)
  • Never give up a known shelter for uncertainty -- a car is one of the worst places to be in a tornado
  • The rise of tornado tourism has caused "chaser convergence" events that have clogged roads and blocked a safe escape route
• Travelers:
  • Go to safe locations -- rest areas and permanent buildings (offer possibilities if tornadoes are crossing major highways)
  • Don't take shelter under bridges. Contrary to urban legend, an overpass is not a safe place.
  • Don't stop in lanes of traffic. Traffic jams have resulted from people stopping on highways, trapping hundreds of people in their cars.
  • (Convert mile markers to nearby exits -- people can't always read mile marker posts in heavy rain)
• Why we repeat so often:
  • Young children may be home alone and not know what to do
  • People who are hard of hearing or who don't have radios turned up
  • Travelers going through
  • Same reasons we listen to flight safety briefings every flight
• Stay indoors
  • The same conditions that are present with tornadoes also tend to be present with the risk of large hail
  • Avoid windows
• Safety precautions
  • Cover your head, if possible, with blankets or even a football/bicycle/motorcycle helmet -- but do not sacrifice time searching for a helmet. The most important factor is getting to a basement or (if one isn't available) to the lowest floor of a sturdy building. Do not substitute a helmet for getting to a safer location.
  • SPC tornado safety guidelines
• FAQs about tornadoes

Flash flooding

• Turn around, don't drown
• "A mere six inches of fast-moving flood water can knock over an adult. It takes only two feet of rushing water to carry away most vehicles. This includes pickups and SUVs."
• "If you come to an area that is covered with water, you will not know the depth of the water or the condition of the ground under the water. This is especially true at night, when your vision is more limited.
• "Overland flooding, the most common type of flooding event typically occurs when waterways such as rivers or streams overflow their banks as a result of rainwater or a possible levee breach and cause flooding in surrounding areas."
• "Do not attempt to drive through a flooded road. The depth of water is not always obvious. The road bed may be washed out under the water, and you could be stranded or trapped."
• "Six inches of water will reach the bottom of most passenger cars causing loss of control and possible stalling."
• "If the vehicle stalls, abandon it immediately and seek higher ground. Rapidly rising water may engulf the vehicle and its occupants and sweep them away."

Resource pages

• Des Moines WFO preparedness page
• Des Moines WFO tornado safety advice
• Des Moines WFO hail and wind safety
• Des Moines WFO lightning safety