Thursday's Severe Weather Awareness Week topic is Severe Thunderstorms. They are more frequent in the Tennessee Valley than tornadoes, and with a slight chance of them occurring late tonight into early Friday, here is some useful information.
A severe thunderstorm is a thunderstorm that produces one or more of the following: hail that has a diameter of one inch or larger, winds greater than or equal to 58 mph, and tornadoes. About 10% of all thunderstorms in the U.S. meet severe criteria. Severe thunderstorms can occur at any time of year, although the most common time of occurrence in the South is during the spring months of March, April, and May. There is also a lesser known secondary season during the fall, in November and early December.
Many people believe that a car is a safe place to be during a lightning strike because of the rubber tires. However, the real reason has nothing to do with rubber tires. The conductive metal frame of the automobile actually protects a vehicle's occupants during a lightning strike by directing the electrical current around the passenger compartment. There is no electrical field inside a hollow conductive shell, which means the charge from the lightning will travel along the metal frame and not inside of your car. As long as your car has a fully enclosed metal top, and you don't touch any conductive parts connected to the outside surfaces, you should be safe in your car.
• Have a plan. Prepare ahead of time so you and your family know what actions to take when severe weather occurs.
• Get indoors! There is no safe place outdoors during a thunderstorm.
• Stay informed! When severe weather threatens, stay tuned to NOAA Weather Radio, local television and radio stations, or the National Weather Service web page at www.weather.gov for up
to date information on the weather situation.
• Know what county you are in. When a warning is issued, the threatened area will be identified
by the counties that contain it.
• Have a NOAA Weather Radio. This is the best way to receive the latest and most up to date weather information from the National Weather Service.
The difference between a watch and warning:
A severe thunderstorm Watch means that conditions are favorable for severe thunderstorms to develop. These are issued by the Storm Prediction Center in Norman, Okla., typically before severe weather is developing. A severe thunderstorm Warning means that a severe thunderstorm has either been indicated on radar or witnessed by storm spotters firsthand. Your local NWS Forecast Office issues these when severe weather is developing or occurring.
Wednesday's topic for Severe Weather Awareness Week is tornado safety. A statewide tornado drill was conducted at 9 a.m. EST today which featured messages over the Emergency Alert System and NOAA weather radio.
A tornado is a violently rotating column of air that extends from the base of a storm cloud to the
ground. Some conditions that are conducive for tornado formation include warm, moist, unstable air,
strong atmospheric winds that increase in speed and change direction with height, and a forcing
mechanism to lift the air. When a combination of these factors comes together just right, tornadoes
form. The most common time of year for tornado formation in Tennessee is during the spring months of March, April, and May, with a secondary tornado season in November and December. Additionally, the afternoon and evening hours are the times of day at which most tornadoes occur, as they are the times at which the maximum heating takes place. However, tornadoes can occur at any time of day and at any point during the year, given the right environment.
To protect yourself before a tornado strikes, be alert to changing weather conditions.
If you see approaching storms or any of the danger signs, be prepared to take shelter immediately.
|If you are in:||Then:|
|A structure (e.g. residence, small building, school, nursing home, hospital, factory, shopping center, high-rise building)||Go to a pre-designated shelter area such as a safe room, basement, storm cellar, or the lowest building level. If there is no basement, go to the center of an interior room on the lowest level (closet, interior hallway) away from corners, windows, doors, and outside walls. Put as many walls as possible between you and the outside. Get under a sturdy table and use your arms to protect your head and neck. Do not open windows.|
|A vehicle, trailer, or mobile home||Get out immediately and go to the lowest floor of a sturdy, nearby building or a storm shelter. Mobile homes, even if tied down, offer little protection from tornadoes.|
|The outside 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.
Never try to outrun a tornado in urban or congested areas in a car or truck. Instead, leave the vehicle immediately for safe shelter.
Watch out for flying debris. Flying debris from tornadoes causes most fatalities and injuries.
Thursday's topic will be Severe Thunderstorms.
We continue Severe Weather Awareness Week Tuesday with the topic of lightning. Nationwide in 2010, 29 people were killed by lightning. Fortunately, none of those killed were in the Volunteer State. Since 1959, a staggering 3,948 people in the United States, including 140 in Tennessee, have died. As a result, Tennessee is in the Top 5 of states in terms of lightning fatalities.
In an average year, 25 million lightning strikes are recorded across the United States alone.
Lightning is an incredibly powerful electrical discharge, containing up to 100 million volts
of electrical charge and capable of reaching 50,000 degrees Fahrenheit. Cloud-to-ground lightning is the result of incredible differences in electrical charge between thunderstorms
and the earth's surface. The sound of thunder travels around one mile every five seconds and is often audible up to 10 miles. If you can see lightning and hear thunder at your location,
you are in danger of being struck by lightning and your life is in immediate danger.
Here are rules for safety:
-Stay away from windows
-Avoid telephones and electrical appliances
(wires connecting to these devices
run outside of the home and act as
-Don't wash dishes or take a shower. The
pipes will conduct electricity.
-Unplug computers and other sensitive
electrical devices. Surge suppressors
may not protect these items if lightning
hits close to home.
Lightning can strike twice, and often will.
Wednesday's topic will be tornadoes. A statewide tornado drill will be conducted, so don't be alarmed if you hear tornado sirens or your weather radio alarm.
by Nick Austin
Channel 3 Storm Alert Meteorologist
Severe Weather Awareness week for TN continues Monday with the topic of flooding and flash flooding. Each year, more deaths occur due to flooding than from any other severe weather related hazard. The Centers for Disease Control report that over half of all flood-related
drownings occur when a vehicle is driven into hazardous flood water. The next highest percentage of flood-related deaths is due to walking into flood waters. Why? The main reason
is people underestimate the force and power of water. Many of the deaths occur in automobiles as they are swept downstream. Of these drownings, many are preventable, but too many people continue to drive into flooded roadways. Most flood-related deaths can be avoided and we want everyone in the TN Valley to be safe during heavy rains. So if you come upon areas covered with water please follow this simple advice: Turn Around, Don't Drown™.
Tuesday's topic will be Lightning, often called the underrated killer.
by Nick Austin
Channel 3 Storm Alert Meteorologist
CHATTANOOGA, TN (WRCB-TV)--Severe Weather Awareness Week this year for the state of Tennessee is February 20-25. Throughout the week the National Weather Service, Tennessee Emergency Management Agency, and other supporting groups will conduct educational activities and drills to help people prevent injuries and deaths from tornadoes, damaging winds, flash floods, lightning, and hail. Each day of the week focuses on a specific type of severe weather or on the warning and drill system.
Today's topic is weather spotting. SKYWARN® is the National Weather Service (NWS) program to recruit and train storm spotters who serve as the ears and eyes that can share the "ground truth" with forecasters. SKYWARN® spotters enhance storm detection capabilities by identifying and reporting potentially dangerous weather conditions. Despite sophisticated technology in use by NWS, forecasters still rely on storm spotters. Doppler radar may indicate that a storm may be producing large hail, damaging winds, or even a tornado, but it cannot tell exactly what's happening on the ground underneath the storm. Anyone can become a volunteer SKYWARN® spotter if they value the satisfaction of knowing that their reports result in better warnings which save lives. NWS also has espotter, a web based program that lets spotters send reports online in real time. The e-spotter program is at: http://espotter.weather.gov
Here are the next spotter training classes available in the Channel 3 viewing area:
Tuesday, March 15, 2011
Athens, TN (McMinn Co.)
McMinn Co. EOC/911 Center
1107 S. Congress Pkwy.
Thursday, March 17, 2011
Cleveland, TN (Bradley Co.)
Bradley Co. EMA Office
1555 Guthrie Drive NW
Monday's topic will be Flooding and Flash Flooding