Severe Weather Toolkit

1.2 Tornadoes

Severe weather happens frequently in Texas. Every area of the state is vulnerable to the threat of tornadoes common in Texas thunderstorms. Though tornadoes can happen at any time of the year, they mostly occur during spring and summer. A tornado is a violently rotating column of air extending from a thunderstorm to the ground. Tornadoes strike with incredible velocity, with winds that can approach 300 miles per hour (MPH). These winds are capable of uprooting trees and structures, and can also turn harmless objects into dangerous projectiles in just a few seconds.

Predicting the exact path of a tornado is difficult, however in most cases, the National Weather Service All-Hazards Monitoring System/Weather Radio makes public announcements to give warnings about potential severe weather conditions. WEAs may also send reports to cell phones to provide some warning as well. These systems provide notifications of hazards, including severe thunderstorms, tornado watches or warnings. It is important, however, to understand the difference between a watch and a warning. A tornado watch is normally issued by the National Weather Service when conditions are favorable for the development of a tornado in and close to the watch area. A tornado watch is usually issued for a period of several hours, and is normally issued well in advance of an actual severe weather incident. Note that, during a tornado watch, it is important to monitor weather statements and be alert for the possibility of approaching storms. Also, remind staff of procedures and locations for tornado sheltering. On the other hand, a tornado warning is issued when a tornado has been sighted, or is indicated by weather radar. Note that a tornado warning can be issued without a tornado watch being issued. During a tornado warning, protective actions should be followed to move students and staff into the areas of the school identified as being the safest.

Campuses should monitor local news for weather updates. When dangerous severe weather or a tornado is approaching the area, administrators must be prepared to take immediate action for the safety of the students and staff. Moving students and staff indoors is important, especially if there is a threat of lightning. Each building may have a unique design and structure, therefore specific areas for sheltering must be identified prior to a severe weather event. By utilizing the protective actions contained in the district or campus emergency operations plan (EOP), staff should 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 to more structurally sound facilities.
  • 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 Tornado 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 and post signage identifying designated severe weather shelter areas. During drills, move occupants into those areas. Occupants should be provided instructions regarding 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 imminent.

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Designate staff members to be responsible for shutting off the gas and electricity. During a drill have designated staff simulate shut off procedures by going to the shut-offs. Do not shut down the system in a drill.

These guidance concepts should be integrated into the campus or facility emergency plans. Seek additional information from structural engineers, facility staff, and local resources to understand the best location for tornado shelters. Also, work with local emergency management officials, meteorologists and first responders to develop EOPs, conduct trainings and drills for your schools to use during severe weather events.

Tornado Resources

Tornado Watch and Tornado Warning Checklists

References

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