Hazardous Weather Education

Severe weather occurs across the United States and around the globe. Learn about flooding, hail, hurricanes, tornadoes, and damaging winds as we take a look inside severe weather.

Severe weather can occur nearly anywhere at anytime. Let's take a look at different forms of severe weather and other hazards. Click on a title and jump to the specific section.

Jump to: Flooding | Hail | Lightning | Hurricanes | Tornadoes | Damaging Winds

Thunderstorms occur around the world every day of the year. In fact, storms are a normal cycle in the earth-atmospheric exchange system. Chances are you've been in a countless number of average thunderstorms. However, nature can become violent. When atmospheric conditions favor, severe and unusual weather can occur (sometimes with little or no warning). Let's dissect the most common forms of dangerous weather.

Flooding

The most common type of dangerous weather is flooding. Recurring storm activity may increase the chance of flooding in your area as storms produce heavy rain over already saturated grounds. Other factors also increase the chances of flooding such as locations that are low-lying, near any body of water, and especially downstream of dams.

Flooding can occur quickly. It's important to pay close attention to forecast information and warnings. If a flood warning is issued for your area, seek higher ground immediately. Rapid flooding can include fast moving water powerful enough to lift cars, houses, and easily overtake any good swimmer. Never cross waters of unknown depth.

top

Large Hail

Any storm can produce hail. Severe hail comes in many sizes starting at 3/4" (three quarter inch a.k.a. "dime size") in circumference. At this size, The National Weather Service considers the storm to be severe. The strength of the updraft will determine the size of the hail. Stronger thunderstorm updrafts can produce hail as large as basketball in size (recorded in history). At basketball size, hailstones can puncture roofs and floors causing external and internal damage.

Severe hail is extremely dangerous and destructive. Never try to drive in severe hail. Large stones can easily break glass, puncture many surfaces, and even injure humans. If you experience this type of severe weather you may also be at higher risk of being hit by a tornado. Read more in the tornado section for further details.

Always stay away from windows and move to an interior reinforced room on the lowest floor of a sturdy well built structure.

top

Lightning

Lightning is another danger from thunderstorms. As the atmosphere discharges electricity, leaders form powerful bolts. Although not considered to be severe alone, it is just as deadly. Bolts can be as hot as 50,000 degrees Fahrenheit. That's hot enough to fuse materials together, destroy structures, start fires, and definitely kill humans. Since lightning can move fractionally close to the speed of light (speed depending on the discharge and electrical properties of the atmosphere), there is no need to argue - one should not try to outrun strikes.

Your best bet for protection is to go indoors and stay away from windows. Lightning loves tall objects which are also made of conductive material. Telephone polls, towers, tall buildings, trees, and other objects are no place of safety during an electrical storm.

top

Hurricanes

A hurricane is an organized tropical storm with winds at or over 74 miles per hour. Any hurricane can also contain other forms of severe weather such as tornadoes and of course flooding. The perfect conditions for a hurricane include warm moist water and relatively weak winds above them.

The National Hurricane Center predicts tropical storms. They are the agency which issues hurricane watches and warnings in the United States. On average, we experience at least five hurricanes per year.

Of the entire hurricane, the most dangerous weather often occurs near the eye wall of the storm. This relative clearing or "eye" of the storm is the center of counterclockwise rotation. High winds, tornadoes, and strong storm surges occur along the bands originating from the eye wall.

The size of a tropical storm system can be quite large - often several hundred miles in circumference. Thankfully energy is spread out over this distance as opposed to relatively smaller scale systems such as individual thunderstorm cells.


top

Tornadoes

Tornadoes are nature's most violent form of severe weather. Any severe thunderstorm can produce a tornado. The perfect conditions for a tornado include a supportive storm cell capable of producing a mature updraft or "Mesocyclone". Mature storms can become self supporting enabling them to live for long periods causing damage even across state lines. While it is possible for a tornado to occur without a classic Mesocyclone, the most dangerous often occur with it. There are many warning signs.

When conditions are favorable, your area made be included in a Tornado Watch. At this time you should pay close attention for any rapidly changing weather conditions. Just because it's clear outside doesn't mean you let your guard down. Awareness is vital here, as your life may depend on it. Large hail and high winds may also be a sign of impending tornadic activity. Rain free areas may also indicate your location is close to the updraft area of a severe thunderstorm. Pay close attention to media and your weather radio for any possible warnings.

If a tornado is indicated by radar or spotted by a person - a tornado warning is issued. At this time you should seek shelter in a sturdy structure away from windows on the lowest floor (find a central location in the structure). Cover your head with a mattress or pillow. Mobile homes are no place to be during a tornado. Abandon the mobile home unit if possible finding a ditch or nearby shelter (if time permits). If you are in a car, leave the vehicle, find a ditch, lie down, and cover your head. Be aware of possible flooding that may occur. Do not hesitate to take action.

There is no such thing as an "all clear" siren. It is also possible for more than one tornado to strike. Do not come out of shelter until cleared by officials, news media, or weather radio notification at the time the warning expires. Professionals will let you know when it's safe to come out or the threat has ended. Remember just because you can't see something yourself, doesn't mean it's not happening. Treat every warning the same - as if your life depended on it. Always have a plan of action for your family, business, or organization ahead of time.

top

Damaging Winds

High winds can cause extensive property damage and injury. The National Weather Service considers winds severe when they reach or exceed 58 miles per hour. Damage can occur at this wind speed causing tree branches to break, windows to shatter, and weak structures to tear apart. Damage becomes more serious as wind speeds increase.

Straight line winds and down bursts can be just as damaging as tornadoes. The most common type of storm producing this kind of severe weather is called a "bow echo" because of its curvature (representing a bow). Dangerous winds can occur at the center of (and along) the bow echo. Remember other types of severe weather may also be occurring.


top