Spending time outdoors with the family can make for an enjoyable excursion. Whether you are at a park playing on playground equipment, hiking, bird-watching, swimming, or even just hanging out in the backyard, the fresh air can be pleasantly invigorating. However, the weather can change in an instant. You may have little warning before severe weather rolls in. Severe weather can involve thunderstorms, lightning, hail, tornadoes, flash floods, high winds, and even hurricanes. Seasonal weather may also include heat waves and blizzards. Depending on your location, you may also need to be prepared for earthquakes. With safety as a priority, it's crucial to monitor the weather so you are prepared for any type of weather condition, especially when you are outdoors.
How Does Severe Weather Form?
Severe weather includes a variety of types of storms. The type of storm depends on the time of the year, the geographic location, and other environmental conditions that may be present. For example, a thunderstorm occurs when unstable air of differing temperatures collides. Warm air near the ground rises quickly, rushing into colder air. When this occurs, the storm brews. Winter storms occur when cold air near the surface of the Earth mixes with moisture. Rising air brings clouds and resulting precipitation, usually in the form of snow or ice.
- Severe Weather Definitions
- Extreme Weather Events
- Understanding the Link Between Climate Change and Extreme Weather
- Extreme Weather
- Weather Dangers
- Preparing for Severe Weather (PDF)
Thunderstorms and Lightning
A thunderstorm is a type of storm that involves, rain, wind, thunder, and lightning. Convection is the upward movement of warm air from the surface of the Earth. When this occurs, the moisture that moves with the air often produces a thunderstorm. Thunderstorms can involve high winds, hail, and tornadoes. Thunderstorms can occur at virtually any time of the year if the weather conditions are right. However, they happen most often during the spring and summer months. Lightning is a frequent occurrence during a thunderstorm. Hearing thunder indicates that lightning is in the immediate vicinity, presenting a significant danger. For optimal safety, people should move indoors as quickly as possible upon hearing thunder. Remain indoors for a minimum of 30 minutes after the final sound of thunder.
- Hazards: Severe Weather
- What Makes a Thunderstorm?
- How Do Thunderstorms Form?
- Severe Weather
- Severe Weather Overview (PDF)
Winter storms and blizzards can occur in areas of the world where the temperature falls below freezing. To meet the criteria for a blizzard, winds must be sustained or frequently gusting at a minimum of 35 miles per hour, lasting for a minimum of three hours. When these conditions occur, snow will be falling and blowing heavily, making it difficult to see. Preparedness is a key for winter storms and blizzards. Because of the possibility of a power loss, families must have food and water on hand. Flashlights, batteries, and an alternate way of heating a home, such as a fireplace or a wood-burning stove, are crucial. In the absence of an alternative source of heat, a family may need to be prepared to move to a shelter or other location. Travel can be dangerous during a winter storm. Therefore, if the potential for a power loss is great, seek alternative shelter before the snow begins.
- Severe Winter Weather
- Winter Storms and Blizzards
- Winter Weather Threats
- How Climate Change May Lead to Bigger Blizzards
- Great Plains Blizzards (PDF)
Tornadoes are violent circling columns of air that extend down from a thunderstorm cloud. When tornadoes touch the Earth, they move along the ground with ferocious strength and intensity. Scientists classify the intensity of tornadoes with the Fujita Scale. A weak tornado would be an F0, while the strongest tornado would be an F5. When a tornado threatens, people must seek immediate shelter. When outdoors, find shelter in a sturdy building as quickly as possible. Park and play equipment will not provide adequate protection. A tornado can devastate virtually any type of building, and flying debris will be a significant danger. Seek shelter in a basement if possible. If a basement is unavailable, go to an interior area of a house on the first floor. A bathroom, closet, hallway, or under a stairwell would be the safest locations. Avoid windows, and find something sturdy to hide under, such as a table or a mattress. Remain in a sheltered location until all threat of the storm passes.
- Tornado Information
- Tornado Facts and Safety Tips
- Tornadoes and Severe Weather
- Tornado Basics
- Get Ready for Tornadoes
- Tornado Safety (PDF)
Hurricanes also involve rotating winds, except these storms form over warm ocean water. Clouds present over the ocean can pull moisture and air up, which forms a column of air. Differences in air temperature cause the air to move in a circular motion. Once wind speeds reach 35 miles per hour, a storm is classified as a tropical storm. A storm reaches hurricane status when winds climb to 74 miles per hour. Hurricanes can have a full diameter of 400 miles or more. The center of the hurricane, called the eye, might be as much as 20 miles in diameter. When a hurricane reaches land, it brings high winds and heavy rain with it. The storm surge from the wind and rain often causes heavy flooding. When a hurricane approaches, officials generally implement an evacuation plan to prevent injuries and loss of life. To preserve property, homeowners must cover windows and secure items so they cannot become airborne.
- How Does a Hurricane Form?
- What Is a Hurricane?
- Hurricane Information
- Hurricanes and Tropical Storms
- Tropical Storm Season: Know Before You Go
Flooding occurs with rising water. A flood can occur when too much rain falls, causing bodies of water to spill over from their natural confines. Coastal areas may have a risk of flooding from the ocean. A floodplain is an area of land at risk of flooding. If an approaching storm involves a risk of flooding, heed warnings. Stock emergency supplies such as fresh water, non-perishable food, flashlights, batteries, and a first aid kit to ensure preparedness. If a home evacuation is necessary, turn off the gas and utilities at the main source prior to leaving.
- Flood Safety Checklist (PDF)
- Floods and Your Family (PDF)
- Preparing a Home That Will Be Flooded
- Flash Floods (PDF)
- Floods and Flooding
Hail is solid precipitation that falls to the ground as clumps of ice. A hailstorm may occur in conjunction with a thunderstorm when the winds moving upward freeze the moisture in a cloud. While injuries from hail are possible, property damage is the most typical result of hailstorms. Hail varies in size, from a quarter-inch in diameter to 1 inch or more. Severe hail could be as large as a grapefruit or even a softball.
- Severe Weather Hazards
- How Does Hail Form?
- Hailstorms Across the Nation (PDF)
- Trends in Hail in the United States
- Hail of a Storm
The Earth has specific fault zones where plates slide, stretch, squeeze, or crash into each other. Movements along fault zones can occur in various ways, depending on the specific geographic location. When these movements occur, an earthquake happens. Typically, stress accumulates between these plates. At some point, the stress releases violently, which sends out waves of vibrations. Scientists use a numerical scale to determine the magnitude of an earthquake. An earthquake that measures between 3 and 5 is light. Quakes measuring between 5 and 7 are moderate, and anything above 7 is major or even greater. People living in fault zones must be aware of earthquake safety guidelines. Heavy moving objects will be a significant risk during an earthquake. When an earthquake occurs, people must drop, cover, and hold onto something secure until the shaking stops. Actions after an earthquake depend on the level of damage. Evacuation may be necessary.
- Earthquake Preparedness
- Why Do Earthquakes Happen?
- Introduction to Elastic Rebound Animation
- What Causes Earthquakes?
- Earthquakes and the Earth's Interior
Find more about the author: Kim Hart