Severe Weather Toolkit

1.3 Severe Thunderstorms and Hail

Severe thunderstorms pose threats to schools and school activities. The threat of lightning associated with severe thunderstorms can have deadly consequences. Schools should include protective actions in their emergency operation plans for lightning and severe thunderstorms. Thunderstorms can form quickly therefore, school staff need to monitor weather updates and follow watches and warnings in order to stay informed of weather conditions in their area.

A severe thunderstorm watch is issued by the National Weather Service when conditions are favorable for the development of severe thunderstorms close to the watch area. Severe thunderstorm watches are usually issued for several hours and in advance of the actual occurrence of the severe weather incident. During a severe thunderstorm watch, it is also important to monitor weather statements and be alert for the possibility of approaching storms. Remind staff of procedures and locations for severe weather sheltering.

A severe thunderstorm warning is issued by the National Weather Service when indicated by radar or sighted. Lightning frequency is not a criterion for issuing a severe thunderstorm warning but lightning often accompanies a thunderstorm. Warnings are issued for shorter periods of time and can be issued without a severe thunderstorm watch being released.

As severe thunderstorms can produce tornadoes, protective actions should follow those actions developed for a tornado. High winds and large hail are often associated with a severe thunderstorm. Protective actions should be implemented to avoid exposure to damaging hail.

Using protective actions contained in the emergency operations plan (EOP), staff must direct all students, staff and visitors into the safest locations in an organized manner.

District and school staff must be aware of quickly changing conditions and make decisions based on the evolving situation. This is why customized planning, training and exercising is essential for each district facility.

Important General Considerations

  • Students in locations of weak construction such as portable classrooms or outbuildings should be moved into more structurally sound buildings.
  • Avoid areas with expansive roofs such as cafeterias, gymnasiums, libraries and auditoriums.
  • Areas and rooms with large exterior windows should be avoided, as they may shatter and expose occupants to flying glass and debris. When using hallways as a sheltering location, keep occupants at least 30 feet from exterior doors and windows.

Suggested School Severe Weather Sheltering Areas

  • Small interior rooms (with short roof spans) and restrooms
  • Interior hallways away from exterior doors with interior load-bearing walls
  • Hallways with external exits can be used but do not shelter anyone within 30 feet of the exit doors or external windows
  • If possible, take refuge on ground level or lower floors.

Use a floor plan to indicate areas where individuals should seek protection from severe weather. Post signage identifying severe weather shelter areas. During drills, move occupants into those areas. Occupants should be instructed on how to take a tornado safe position. Have occupants sit and face the walls. Instruct them to crouch and cover the back of their head and neck, linking their fingers. Demonstrate the protective posture and have them practice it. Do not expect them to hold the posture for long periods unless a threat is eminent.

Athletic events and other outdoor activities are vulnerable to lightning strikes. Hence, it is important to monitor weather conditions for any outdoor activities. Emergency operation planning should include protective actions for moving large numbers of people into storm protected areas, should severe weather and/or lightning occur.

Protective Actions From Lightning

  • Establish a chain of command that identifies who is designated to make the decision to remove individuals from the field.
  • Name a designated weather watcher (An individual who actively looks for signs of threatening weather and notifies the chain of command if severe weather becomes dangerous).
  • Have a means of monitoring local weather forecasts and warnings.
  • Designate a safe shelter for each venue.
  • When thunder is heard within 30 seconds of a visible lightning strike, or a cloud-to-ground lightning bolt is seen, it means that the thunderstorm is close enough to strike your location with lightning. Therefore, it is important for schools to suspend play or activities for thirty minutes and take shelter immediately.
  • Once activities have been suspended, wait at least thirty minutes following the last sound of thunder or lightning flash prior to resuming an activity or returning outdoors.
  • Avoid being at the highest point in an open field, in contact with, or in proximity to the highest point, as well as being on the open water. Do not take shelter under or near trees, flagpoles, or light poles.
  • Assume a lightning safe position (crouched on the ground with weight on the balls of the feet, feet together, head lowered, and ears covered) for individuals who feel their hair stand on end, skin tingle, or hear "crackling" noises. Do not lie flat on the ground.

Observe the following basic first aid procedures in managing victims of a lightning strike:

  • Activate local emergency medical services (EMS) by calling 911.
  • Lightning victims do not "carry a charge" and are safe to touch.
  • If necessary, move the victim with care to a safer location.
  • Evaluate airway, breathing, and circulation, and begin cardiopulmonary resuscitation (CPR) if necessary.
  • Evaluate and treat for hypothermia, shock, fractures, and/or burns.
  • All individuals have the right to leave an athletic site in order to seek a safe structure if the person feels in danger of impending lightning activity, without fear of repercussions or penalty.

Severe Thunderstorm and Hail Resources

Thunderstorm Watch and Warning Checklists

References

National Weather Service (2014). National Oceanic and Atmospheric Administration. Retrieved from http://www.nws.noaa.gov/om/severeweather/index.shtml

University Interscholastic League; Recommendations for Lightning Safety. Retrieved from https://www.uiltexas.org/health/info/lightning-safety