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Adverse Weather

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Tornadoes are nature's most violent storms. Spawned from powerful thunderstorms, tornadoes can cause fatalities and devastate an area in seconds. A tornado appears as a rotating, funnel-shaped cloud that extends from a thunderstorm to the ground with whirling winds that can reach 300 miles per hour. Damage paths can be in excess of one mile wide and 50 miles long. Every state is at some risk from this hazard.

Some tornadoes are clearly visible, while rain or nearby low-hanging clouds obscure others. Occasionally, tornadoes develop so rapidly that little, if any, advance warning is possible.

Before a tornado hits, the wind may die down and the air may become very still. A cloud of debris can mark the location of a tornado even if a funnel is not visible. Tornadoes generally occur near the trailing edge of a thunderstorm. It is not uncommon to see clear, sunlit skies behind a tornado.

The following are facts about tornadoes:

  • They may strike quickly, with little or no warning.
  • They may appear nearly transparent until dust and debris are picked up or a cloud forms in the funnel.
  • The average tornado moves Southwest to Northeast, but tornadoes have been known to move in any direction.
  • The average forward speed of a tornado is 30 MPH, but may vary from stationary to 70 MPH.
  • Tornadoes can accompany tropical storms and hurricanes as they move onto land.
  • Waterspouts are tornadoes that form over water.
  • Peak tornado season in the southern states is March through May.
  • Tornadoes are most likely to occur between 3 p.m. and 9 p.m., but can occur at any time.

Tornado Watch
Tornadoes are possible. Remain alert for approaching storms. Watch the sky and stay tuned to NOAA Weather Radio, commercial radio, or television for information.
Tornado Warning
A tornado has been sighted or indicated by weather radar. Take shelter immediately.

What to do during a Tornado

If you are under a Tornado WARNING seek shelter immediately!

The best place to be in the event of a tornado is the interior of a building with no exterior windows. If possible get to the lowest point of the building such as the basement.

If you are in a vehicle, do not try and outrun the tornado. Exit the vehicle as soon as possible and seek shelter in the interior of a building.

If you are stuck outside in a tornado with no shelter, lie flat in a nearby ditch or depression and cover your head with your hands. Be aware of the potential for flooding. Do not get under an overpass or bridge. You are safer in a low, flat location. Watch out for flying debris. Flying debris from tornadoes causes most fatalities and injuries.

While most of the buildings on campus are sturdy and should be able to weather a tornado there are a people who work in trailers. If you work in a trailer and there is a Tornado WATCH, evacuate your trailer and seek shelter in the nearest safe building. If you have any questions as to where you should go in the event of a tornado please call EHS at 962-5507.

Tornado Watch and Warning Preparation for Laboratories

The following list is developed to help you prepare your lab and protect your research assets. Consider the following:

  • Complete existing experiments to a termination point. Do not start any new experiments. Shut down equipment if hazardous conditions may result from loss of utilities ( ie., loss of coolant, vacuum, steam for autoclaves).
  • If you plan to complete experiments during the inclement weather event:
    • be prepared to provide your own basic necessities
    • be prepared to terminate experiments immediately if conditions deteriorate
  • Plug refrigerators and freezers into emergency power where available. Red outlets are typically connected to emergency power. Avoid opening freezers and refrigerators to maximize cooling ability.
  • Secure and protect valuable research samples, radioactive isotopes, biohazardous agents, recombinant materials and hazardous chemicals to prevent breakage and release.
  • Secure chemical, radioactive, and biological waste.
  • Fill Dewars and cryogen reservoirs for critical sample storage.
  • Secure all other regulated materials.
  • Confirm that arrangements have been made for the care of laboratory animals.
  • Remove equipment, chemicals, wastes and supplies from the floor in areas that may flood.
  • Breakable items or items that may become airborne in heavy winds should be moved away from outside windows.
  • Ensure all gas cylinders are secure. Cylinders not currently in use should be capped and secured.
  • Close fume hood sashes.
  • Unplug computers, printers, and all other electrical equipment (except refrigerators and freezers).
  • Cover and secure or seal vulnerable equipment with plastic.
  • Protect valuable files, research notebooks, and data to a safe secure location. Assist colleagues in securing their materials where possible.
  • Back-up computer files, make more than one copy and store in several different locations.
  • Check emergency phone numbers. Update emergency notification lists on lab doors. Add temporary contact information if staying in a different location.
  • Take personal valuables with you.

Things to Remember

If Orange County is placed under a tornado warning, the University will activate the sirens as part of ALERT Carolina to indicate the situation has become imminent and life-threatening. You will need to take immediate precautions.

Be prepared to take the following actions if the watch is elevated to a tornado warning:

  • Seek shelter immediately.
  • Move to an interior room on the lowest floor of a sturdy building.
  • Avoid windows.
  • If no shelter is available, lie down in a low-lying area.
  • Protect yourself from flying debris.

For more information about all things tornado related check out The Tornado Project website.


All thunderstorms are dangerous. Every thunderstorm produces lightning. In the United States, an average of 300 people are injured and 80 people are killed each year by lightning. Although most lightning victims survive, people struck by lightning often report a variety of long-term, debilitating symptoms. Other associated dangers of thunderstorms include tornadoes, strong winds, hail, and flash flooding. Flash flooding is responsible for more fatalities - more than 140 annually - than any other thunderstorm-associated hazard.

Dry thunderstorms that do not produce rain that reaches the ground are most prevalent in the western United States. Falling raindrops evaporate, but lightning can still reach the ground and can start wildfires.

The following are facts about thunderstorms:

  • They may occur singly, in clusters, or in lines.
  • Some of the most severe occur when a single thunderstorm affects one location for an extended time.
  • Thunderstorms typically produce heavy rain for a brief period, anywhere from 30 minutes to an hour.
  • Warm, humid conditions are highly favorable for thunderstorm development.
  • About 10 percent of thunderstorms are classified as severe - one that produces hail at least three-quarters of an inch in diameter, has winds of 58 miles per hour or higher, or produces a tornado.

The following are facts about lightning:

  • Lightning's unpredictability increases the risk to individuals and property.
  • Lightning often strikes outside of heavy rain and may occur as far as 10 miles away from any rainfall.
  • "Heat lightning" is actually lightning from a thunderstorm too far away for thunder to be heard. However, the storm may be moving in your direction!
  • Most lightning deaths and injuries occur when people are caught outdoors in the summer months during the afternoon and evening.
  • Your chances of being struck by lightning are estimated to be 1 in 600,000, but could be reduced even further by following safety precautions.
  • Lightning strike victims carry no electrical charge and should be attended to immediately.

What to do during a Thunderstorm

Obviously the best thing to do during a thunderstorm is to go inside a building. However if that is not possible and you find yourself outside in the following situations here is what you should do.

  • If you are in a forest or a wooded area seek shelter in a low area under a thick growth of small trees.
  • If you are in an open area go to a low place such as a ravine or valley. Be alert for flash floods.
  • If you are on open water get to land and seek shelter immediately.
  • If you are anywhere you feel your hair stand on end (which indicates that lightning is about to strike), squat low to the ground on the balls of your feet. Place your hands over your ears and your head between your knees. Make yourself the smallest target possible and minimize your contact it the ground. DO NOT lie flat on the ground.

During a thunderstorm, avoid the following:

  • Natural lightning rods such as a tall, isolated tree in an open area.
  • Hilltops, open fields, the beach, or a boat on the water.
  • Isolated sheds or other small structures in open areas.
  • Anything metal - tractors, farm equipment, motorcycles, golf carts, golf clubs, and bicycles.


Tropical storms and hurricanes are easily tracked and have as long an advance warning period as any weather system. However, their intensity, and speed and direction of motion can quickly change.

While UNC is located inland it does not mean that we are not at risk from high winds and rains associated with tropical storms and hurricanes. It is important to take these storms seriously and to plan accordingly.

Four key alerts are issued that relate specifically to tropical storms and hurricanes.

  • Tropical Storm Watch: Tropical storm conditions with sustained winds from 39 to 73 mph are possible in your area within the next 36 hours.
  • Tropical Storm Warning: Tropical storm conditions are expected in your area within the next 24 hours.
  • Hurricane Watch: Hurricane conditions (sustained winds greater than 74 mph) are possible in your area within 36 hours.
  • Hurricane Warning: Hurricane conditions are expected in your area in 24 hours or less.

Office Environment

  • Move and secure valuable items in your office away from exterior windows.
  • Lock windows and draw drapes or lower the blinds.
  • Back up personal computer data and software then shut down computers and printers.
  • Store the software and data disks in a dry place off the ground, such as the top drawer of a file cabinet.
  • Unplug electrical equipment such as computers, printers, clocks, radios etc. from outlets.
  • Cover large valuables, such as computers and printers, with plastic or some other material for protection.
  • If your office is below ground, store all your valuables well above the floor.
  • If caught in a building during the hurricane, stay inside away from windows and near the center of the building.

Laboratory Environment

Hurricanes are dangerous storms and can threaten the safety and operation of research laboratories. Plans should be developed well in advance of a hurricane to insure the protection of valuable research equipment, specimens and data. Once a hurricane watch is issued, these plans should be implemented in your research areas in preparation for the hurricane. Even with backup generators available, researchers should protect their valuable materials in case power, water and climate control go out of service for an extended period of time. Special arrangements may need to be planned to protect and prevent release of radioactive isotopes, biohazardous agents and hazardous chemicals. Here are some tips to help prepare for hurricanes:

  • When a hurricane watch is issued, make necessary preparations to suspend ongoing experiments involving biological cultures, radioactive agents and hazardous chemicals.
  • When a hurricane warning is issued, implement activities to suspend operations in the laboratory. Plan to shut operations down within three hours of initial hurricane warning.
  • Remember, don't count on the availability of power, water, climate control, or fume hood exhaust systems.
  • Always keep chemical/radioactive materials in your inventory to a minimum.
  • Reorganize and dispose of old materials routinely to keep chemicals from becoming outdated.
  • Due to the possibility of power outages, materials that are volitile, toxic, or pose a respiratory hazard should not be stored in fume hoods or refrigerators but in tightly sealed, impervious and impact-resistant containers.
  • Laboratories with outside windows should develop a secure area for the storage of water reactive chemicals, radioactive materials and biological agents. These secure areas should be waterproof and heavy enough to not be affected by the wind.
  • Hazardous chemicals, radioactive materials and biological agents should not be stored below ground level during a hurricane. Find a secure area above the ground floor levels to secure these materials in case of flooding.
  • Keep plastic waterproof containers on hand to store reactive chemicals, lab notes, research documentation, computer disks, and any other materials that you cannot afford to have damaged.
  • Keep plenty of warning labels appropriate for the hazards of the materials you work with on hand. These may be needed after the hurricane.

Residence Halls

  • Residence hall staff will provide necessary instructions for emergency procedures. Please act quickly when advised by staff to evacuate to other parts of the building, or make emergency preparations in your room.
  • Remain in the Residence Hall unless advised otherwise by staff. In immediate danger, staff will instruct you to move to lower floors, the basement, hallways, or to evacuate the building.
  • Have access to flashlights. Do not use candles or any open flame lantern, etc. These are highly dangerous in a power outage.
  • Electrical equipment should be unplugged and placed off the floor, preferably in a closet or as far away from windows as possible.
  • Since the floors can get wet, all articles such as shoes, rugs, clothes, bags, suitcases, etc., should be placed on closet shelves, in dresser drawers, or on a bed.
  • All loose objects should be placed in drawers or closets. Papers, books, etc. , should not be left on top of desks or dressers.
  • Valuables should be placed in a theft secure place (or securable location). All doors should be locked when the occupants are not in the room or apartment.
  • All windows and drapes/curtains must be closed tightly.
  • Due to heavy rain and wind, move all personal belongings away from the outside wall(s) in your room.
  • Have a container with some fresh water in case water supply is affected.
  • If caught outside, avoid contact with dangling or loose wires, likewise, do not touch trees or other items outside, because they may conduct electricity.
  • Emergency shelters may be set up at various campus locations. Residence hall students will be instructed of locations should the need to evacuate arise.