Wednesday, February 28, 2018

Severe Weather Awareness 2018: Tornado Safety

The El Reno, OK EF-3 tornado of May 31, 2013, taken from about one mile away by storm chaser Nick Hellums.
Tornadoes are violent columns of rotating air that are produced by severe thunderstorms.  Weak tornadoes produce wind of  65-85 mph, while the strongest (such as the Moore, OK tornado of May 2013), produce wind well over 200 mph and can be a mile wide or larger (the El Reno, OK tornado of May 2013 is the widest on record at 2.6 miles!). Not all severe thunderstorms produce tornadoes, only a small fraction do, but people should be alert for the possibility if and when a Severe Thunderstorm Warning is issued and take action when a Tornado Warning is issued for their location.

Tornado safety rules include:
  • At home or in small buildings, go to the basement or storm shelter, or to a windowless interior room such as a closet or bathroom on the lowest level.  Get under something sturdy such as a table or heavy bed.
  • Abandon mobile homes and vehicles for a sturdy structure. If there is no such structure nearby, lie flat in a ditch, ravine, gully, culvert, or a low spot with your arms and hands shielding your head, staying mindful of possible flooding as well.
  • In large buildings such as at school, shopping centers, hospitals, or factories/warehouses, go to the predesignated shelter area. Interior hallways on the lowest floor are best. Stay out of areas with high roofs or large roof spans, as they typically offer little to no protection from tornadic wind due to weakly supported roofs.
  • At school, children should follow the safety procedures established by school officials. These should include avoidance of areas with high roof spans and glass exposed to the exterior of the school. Children should crouch down next to a wall or under desks or tables and cover the head and neck with their hands.
  • At all times, avoid windows or large panes of glass.
  • If outside and sturdy structures are not available, try to drive to the nearest sturdy structure for shelter.  If one is not available, lie down in an area that is lower than surrounding areas (ditch or ravine if possible) with arms/hands shielding your head (being mindful of potential flash flooding).
  • When taking cover, have shoes on, photo ID on your person, cell phone (preferably charged in advance) with you, and crouch down and protect the back of your neck with your arms and hands.

A Tornado Watch, typically issued for a large area such as several counties, means that conditions are favorable for the development of severe thunderstorms that can produce tornadoes. Stay tuned to NOAA Weather Radio, commercial TV or radio, and other trusted sources for warnings and watch the sky for the possibility of developing severe weather.  Have your plan ready should a warning be issued and be ready to exercise that plan on a moment's notice.

A Tornado Warning, typically issued for a small area in the path of a storm, means that Doppler Radar has indicated the likelihood of a tornado or a tornado has been sighted by spotters or law enforcement.  If you are in the path of the storm (sometimes called "in the polygon" due to the shape of the warnings that are drawn by the NWS), immediately find shelter using the rules above.

A Tornado Emergency is not a warning type, but is issued (usually following the original Tornado Warning) when a large and destructive tornado has been confirmed and is moving into a populated area.  The risk of destruction and fatalities is high and an elevated call-to-action is required.  Everyone in the storm's path should immediately take action.

Storm Shelters

MWN recommends Take Cover Storm Shelters to keep Mid-South residents safe in the path of the storm. We have become very familiar with Take Cover's high-quality products, as well as their outstanding customer service, and have no reservations about endorsing this fantastic company. You can learn more about Take Cover Shelters and their in-ground shelters, which are installed in a concrete slab such as a garage floor, at their website or on Facebook. Be sure to mention MemphisWeather.net when you contact Jessica!

StormWatch+ Alerts

In addition, a personal warning device that only alerts you if YOUR location is in the path of a dangerous storm is a MUST. We encourage you to add StormWatch+ to your MemphisWeather.net app. It will wake you up at night for the most dangerous situations and allow you to customize exactly what locations you want to be alerted for and what types of alerts to receive, as well as when you don't want to be bothered.  The MWN mobile app is available for iPhone and Android devices.

For more information and interesting statistics on Mid-South tornadoes, see this recent study and this comprehensive overview produced by NWS-Memphis. Graphics below published in the second link listed.

Mid-South tornadoes by month. The primary season is spring, but a secondary season exists in the fall. Tornadoes can occur in any month however. Courtesy NWS-Memphis.

Mid-South tornadoes by hour of the day. Most tornadoes occur in the late afternoon to early evening, though they can occur at any time of day. In fact, 46% of Mid-South tornadoes occur at night, which contributes to a high death rate. Courtesy NWS-Memphis.

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