Understanding severe weather is crucial for staying safe, especially when it comes to thunderstorms. But what exactly makes a thunderstorm “severe”? What Are The Characteristics Of A Severe Thunderstorm Select Two? A severe thunderstorm isn’t just any storm with a bit of rain and thunder; it possesses specific characteristics that indicate a higher potential for damage and danger. Let’s delve into two key characteristics that define a severe thunderstorm.
Hail Size: A Tumbling Tale of Atmospheric Instability
One of the hallmark indicators of a severe thunderstorm is the presence of large hail. Hail forms within thunderstorms when strong updrafts carry raindrops into extremely cold regions of the atmosphere, typically above the freezing level. These raindrops freeze, and as they are repeatedly cycled up and down within the storm, they accumulate layers of ice, growing larger and larger. The size of the hail is directly related to the strength of the updraft; stronger updrafts can support larger hailstones, signifying a more intense and potentially dangerous storm.
Hail is classified as severe when it reaches a diameter of 1 inch or greater (about the size of a quarter). Such large hail can cause significant damage to property, including denting cars, breaking windows, and damaging crops. It also poses a risk of injury to people and animals caught in the storm. The process can be summarized in the following list:
- Strong updrafts carry water droplets upward.
- Water droplets freeze in cold air.
- Ice particles cycle up and down, accumulating layers.
- Hailstones grow large enough to overcome the updraft and fall.
The presence of hail is a clear sign of the energy and intensity within a thunderstorm. Below is a comparison of potential hail sizes:
| Hail Size | Approximate Size | Potential Impact |
|---|---|---|
| Less than 1 inch | Pea-sized | Minor damage |
| 1 inch | Quarter-sized | Moderate damage to vehicles and crops |
| 2 inches or greater | Golf ball-sized or larger | Significant damage; potential for injury |
Damaging Winds: A Force of Nature Unleashed
Another defining characteristic of a severe thunderstorm is the presence of damaging winds. These winds are not just a gentle breeze; they are powerful gusts capable of causing widespread destruction. Specifically, a thunderstorm is considered severe if it produces wind gusts of 58 miles per hour (93 kilometers per hour) or greater. These winds can be generated by several mechanisms within the storm, including downbursts, which are concentrated columns of rapidly descending air.
Downbursts occur when rain-cooled air, denser than the surrounding air, plummets to the ground. As this air hits the surface, it spreads out horizontally, creating strong, straight-line winds. These winds can topple trees, down power lines, and even cause structural damage to buildings. Furthermore, the combination of strong winds and heavy rain can significantly reduce visibility, making driving conditions hazardous.
- Downbursts: A major source of damaging winds.
- Straight-line winds: Powerful gusts moving in a linear direction.
- Impact: Fallen trees, power outages, property damage.
Want to learn more about severe thunderstorms and other dangerous weather phenomena? The National Weather Service (NWS) is an excellent resource for in-depth information and safety tips. Visit their website to enhance your understanding and preparedness!