How to Prepare for Major Storms and Weather Events

The greatest expense for companies after a natural disaster is the disruption of operations while attempting to salvage, reboot and replace equipment, typically with limited employee support as they can be occupied with personal matters.

We regularly receive calls from facility managers who have a major storm approaching and worry about damages to their facility, equipment and materials. In fact, we recently talked to a customer who was warehousing computer hardware and was concerned about a hurricane on the way. Sure enough, his roof started leaking once the storm hit, but he avoided damages and downtime by preparing ahead and purchasing leak diverters to keep water from hitting the new computers and other valuables.

Without proper planning, many corporations are left vulnerable to disasters and costly downtime, which is why contingency and business continuity planning are so important.

Storm Risks by Geographic Region

Companies in the United States need to evaluate their risk of major storms, including hurricanes, tornadoes and tsunamis. The storms your facility needs to prepare for depend on where you are located. Keep in mind that flooding is a universal risk that can result from severe storms in almost any region of the country.

Check out the maps below to determine what storms could affect your facility, then keep reading to learn more about specific weather events you could experience.

Hurricanes

Hurricanes are a type of tropical cyclone with severe thunderstorms and winds that can exceed 155 miles per hour. They occur most often in the Atlantic and Gulf of Mexico coastal regions, but can also happen in the southwestern United States and along the Pacific coastlines. The Atlantic hurricane season runs from June to November, with peak season of mid-August to late October.

The torrential rains and high winds of a hurricane can cause widespread destruction. Hurricanes can also cause flash flooding, mudslides, landslides and flooding on rivers and streams. Flooding may last for several days or weeks after a storm.

Hurricanes are classified using the Saffir-Simpson Hurricane scale, which has five categories. Categories three through five are considered “major hurricanes,” although all five categories are dangerous.

Hurricane Terms to Know

Hurricane Warning: When conditions are expected within 36 hours. Complete your preparations and leave the area, if instructed.

Hurricane Watch: When conditions are a threat within 48 hours. Review your plan and begin making preparations.

Hurricane: Intense tropical thunderstorm with sustained winds exceeding 74 miles per hour.

Storm Surge: Water pushed onshore by hurricane or tropical storm winds. Storm surges can be 25 feet high and span 50-100 miles wide.

Storm Tide: A combination of a storm surge and the normal tide.

Tropical Depression: Clouds and thunderstorms with sustained winds not exceeding 38 miles per hour.

Tropical Storm: Strong thunderstorms with sustained winds of 39-73 miles per hour.

Tornadoes

Tornadoes are formed by powerful thunderstorms. They have funnel-shaped clouds that touch the ground. At first, tornadoes are transparent, but as they collect dirt and debris, they become darker and easier to see. Typically, tornadoes move southwest to northeast, but they can change quickly and can move in any direction.

Tornadoes can develop rapidly with little warning and can sometimes be obscured by heavy rains or low-lying clouds. Some of the danger signs preceding a tornado are:

• Dark skies that may appear greenish
• Large hail
• Large, dark and low-lying clouds
• Loud roaring noise, similar to a freight train
• Clouds of debris
• Winds that suddenly die down followed by very still air
• Warm, humid and windy weather conditions

Tornadoes occur most often in the spring and summer months and between 3 and 9 p.m., but they can occur at any time and in any season. Every state is at risk for tornadoes with states east of the Rocky Mountains being at greater risk than states west of the Rockies. Hurricanes, heavy rains, hail and flash flooding may all accompany a tornado.

The National Weather Service classifies tornadoes into five categories using the Enhanced Fujita Scale.

Tornado Terms to Know

Cyclone: A closed, rotating wind in an area of low atmospheric pressure. Cyclones move counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Funnel Cloud: A rotating column of wind that hasn’t touched the ground. When a funnel cloud touches the ground, it is called a tornado.

Landspout: A small, weak tornado that looks like a waterspout.

Multiple-vortex tornado: a tornado that has two or more sub-vortices that circle the center of a larger tornado.

Rope tornado: A tornado that has a long, narrow shape: like a snake. The tornado typically has this shape near the end of its lifecycle.

Supercell: A dangerous thunderstorm that can last for hours and may produce tornadoes.

Tornado Alley: An area in the central United States that extends from central Texas northward to Illinois and Indiana.

Tornado Warning: A tornado has been sighted or detected on weather radar. Take shelter immediately.

Tornado Watch: Weather conditions indicate that a tornado may form in the area.

Tornado: created by thunderstorms; a violent, funnel-shaped windstorm that touches the ground. Also called a “twister.”

Waterspouts: Tornadoes that form over warm water. These can move onshore and cause damage to coastal areas.

Tsunamis

Tsunamis are one of the most infrequent types of natural disasters, but they can strike at any time. Unlike some other types of natural disasters, tsunamis do not have seasons because they are caused by earthquakes, not weather patterns.

Tsunami waves are often confused with tidal waves. Tidal waves are caused by the gravitational interactions between the sun, earth and moon. Tsunami waves are a series of waves caused by earthquakes or landslides that occur deep on the ocean floor. Most tsunami waves are less than 10 feet in height, but some waves can reach more than 100 feet. Unlike tidal waves, tsunami waves do not curl or break.

Coastal communities in the Pacific from California to Alaska and Hawaii are at greatest risk for tsunamis, some of which can hit with little time for official warnings to be made. Some of the natural warning signs of a tsunami include:

• A strong or long earthquake
• Sudden rise or fall of the ocean
• Water receding from the coast or shoreline
• Abnormally large waves
• Unusually strong currents
• A loud roaring sound from the ocean

Tsunami Terms to Know

Distant Tsunami: A tsunami generated by a major earthquake, originating more than 1,000 km or more than 3 hours from its source. Less frequent, but much more hazardous than regional tsunamis.

Local tsunami: A tsunami generated by an earthquake less than one hour from the coast. Most destructive tsunamis are local or regional.

Microtsunami: A low amplitude tsunami that is only observed instrumentally. Not easily detected visually.

Ocean-wide tsunami: See distant tsunami.

Recession: Drawdown of the sea level prior to tsunami flooding, exposing sea bottom, rocks and fish. This is a natural sign that a tsunami is approaching.

Regional Tsunami: A tsunami generally within 1-3 hours from its source. Most destructive tsunamis are local or regional.

Seismic sea wave: Another name for tsunamis.

Teletsunami: See distant tsunami.

Tsunami Advisory: Strong currents and waves that are dangerous to those in or very near water are possible. Take action. Stay out of water and away from beaches or waterways.

Tsunami All-Clear: Notice issued by local authorities when a tsunami warning is cancelled indicating to the public that it is safe to return to evacuated zones. Not the same as a Tsunami Warning Cancellation (TSW).

Tsunami Information Statement: An earthquake has occurred but there is no current tsunami threat.

Tsunami Warning Cancellation (TSW): The cancellation of a warning after damaging waves have stopped coming ashore and sea level readings indicate that the tsunami is below destructive levels. This is not the same as a Tsunami All Clear notice.

Tsunami Warning: Dangerous coastal flooding and possible currents is expected or is occurring. Prepare for flooding. Take action. Move to high ground or inland.

Tsunami Watch: A distant earthquake has occurred and a tsunami is possible. The area included in the watch is determined by magnitude of the earthquake. Be aware. Be prepared to act.

Tsunami: A series of ocean waves that travel at speeds averaging 450 mph, produced by earthquakes or underground landslides below or near the ocean floor.

Floods

Floods are the most common type of natural disaster in the United States and the leading cause of weather-related deaths. Floods can be caused by many different natural or manmade phenomena including hurricanes, tornadoes, tsunamis or sustained heavy rains.

Unlike other types of disasters that tend to be more regional or seasonal in nature, flooding can happen at any time and in every part of the country. Just because an area has never had flooding doesn’t mean that it will never experience one. And, areas that have flooded previously may experience another flood in the future.

Floods vary in nature. Flash floods develop quickly, sometimes within minutes of a rain event. Other floods develop over a period of days, or they may accompany another disaster, such as a tornado or hurricane. Flooding can also occur if a dam or levee breaks.

Flood Terms to Know

100-Year Flood: A statistical estimate that models stream flow peaks over a period of time to determine if a watershed has a 1% chance of flooding in any given year, or a chance of flooding once every 100 years.

Flash Flood Statement: A statement issued to inform the public about current flash flood conditions.

Flash Flood Warning: A life and property threatening flash flood is occurring or will occur within the next six hours. Anyone in a flood prone area should move to higher ground.

Flash Flood Watch: Flash flooding is possible. This is issued when flooding is expected within 6 hours after a heavy rain has ended. Be prepared to move to higher ground.

Flash Flood: A flood in hilly or mountainous areas that occurs after a heavy rain.

Flood Advisory: Announcements issued to advise the public of a minor flood event.

Flood Stage: The point at which a body of water overflows banks onto dry land.

Flood Warning: An 80% chance of moderate or major flooding is occurring or will occur soon. Prepare to evacuate. Evacuate if advised to do so.

Flood Watch: There is a 50% chance of flooding.

Flood: Partial or complete inundation of two or more acres of normally dry land or of two or more properties by tidal waters, runoff of surface waters, mudflow or collapse of land surrounding a lake or other body of water.

Floodplain: Any land area that is susceptible to flooding from any source.

Major Flooding: Flooding with extensive damage to structures and/or roads.

Minor Flooding: Flooding with minimal or no property damage.

Moderate Flooding: Flooding that impacts some buildings and roads near a stream or other body of water.

Now that you know more about the major storms that you could experience, use this checklist to make sure your facility is prepared to handle these weather events. We also included specific steps to take before, during and after each major storm.

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