University of Delaware
Policies and Procedures Manual

Section: Safety & Security
Policy Number: 7-46
Policy Name: Lightning Safety for Outdoor Activities
Date: February 2001

  1. PURPOSE

    To ensure the safety of guests, participants, and staff during outdoor activities and to provide the criteria for suspension and sheltering when lightning is detected approaching or threatening outdoor activities.

  2. BACKGROUND

    Lightning strikes approximately 1,000 people annually in the United States, causing fatalities in about 1/3 of these cases. Most of these cases involve persons in outdoor, open areas during the period preceding, during, or after a lightning storm. Lightning storms move at speeds of 25 mph or more and lightning can strike as much as 30 miles ahead of or following the main rain cell of a lightning storm, striking from a clear blue sky. Because of this, visual means of lightning detection is inadequate. Further, persons must seek shelter in advance of the visual lightning or the main rain cell.

  3. POLICY

    1. All persons managing or coordinating outdoor events or groups that conduct outdoor activities are required to review the procedures outlined in this policy and departmental procedures at least annually.

    2. During the summer thunderstorm season all persons managing or coordinating outdoor events or groups that conduct outdoor activities are advised to monitor the weather forecast by local radio or internet for the potential for lightning or severe weather.

    3. Outdoor events with crowds which will require >10 minutes to evacuate must utilize an electronic detection system for monitoring the presence of lightning in the area when severe weather is forecast or expected.

    4. Outdoor activities with groups that take <10 minutes for evacuation should also use electronic detection systems; however, other recognized means of lightning monitoring may be considered and must be approved for use by the department safety committee or unit administrator.

    5. The event manager or person responsible for conducting outdoor activities shall terminate or suspend activities when directed by Public Safety or their lightning monitoring means indicates the presence of lightning within threatening distances based on the time required to reach shelter. For large outdoor events such as football games, graduation, convocation, etc. the event manager will defer the decision for cancellation to the hightest ranking official available.

    6. Events shall not resume until lightning is no longer detected within the ranges warranted in (E) above.

    A lightning safety reference guide is available at www.udel.edu/OHS/lightningsafety.html. For questions or concerns regarding this policy contact the Department of Occupational Health and Safety at x8475 or Public Safety at x2222.

    Submitted by: Occupational Health and Safety

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    Please direct questions to the Executive VP office.