Oklahomans know tornadoes can be deadly, but we may not always know how to protect ourselves.
In 2013, 24 people lost their lives when an EF-5 tornado hit Moore a day after another tornado destroyed multiple homes in east Norman. The risk of severe weather events such as large hail, tornadoes and flooding are higher in April and May, said National Weather Service meteorologist Wayne Ruff, meaning residents should be especially aware of weather.
“Pay attention to the weather forecasts, not only for today, but for the next two or three days so you can prepare,” Ruff said. “On any given day where there is a forecast for severe weather, think about changing plans that would put you at risk.
"Early warnings are mostly for people who pay attention. If you don't know there's a possibility of a threat, it's more difficult to respond to a warning.”
Between 1950 to 2014, 1,414 tornados occurred in Oklahoma during May, the most tornado-prone month in Oklahoma, according to the National Weather Service. The May 20, 2013, tornado was up to 1.3 miles wide and was on the ground for 39 minutes, tearing a 17-mile path of destruction from Newcastle to Moore.
Watching local weather forecasts and paying attention to National Weather Service warnings on social media and other sites can provide an opportunity to take shelter. In case of a power outage, a weather radio with battery backup is essential, particularly in rural areas where cell phone coverage may be spotty.
“People have to select a methodology of gathering information and follow it,” Norman’s emergency management coordinator David Grizzle said.
• Siren speak and sheltering in place: Despite our intimate and sometimes deadly experience with twisters, Cleveland County residents can be unfamiliar with city policies regarding tornado sirens and shelters.
Norman has 68 and Moore has 38 warning sirens, but people may rely too heavily on the city's sirens or may misinterpret what those sirens mean.
First and foremost, Grizzle wants residents to know sirens are outdoor warning systems designed to alert people who are outside. A person inside a home, business or other structure may not hear a siren.
“Newer construction homes are typically built to suppress outside traffic and neighbor noises. Unfortunately, the sirens are suppressed, as well,” the city of Moore website warns. “Add in the typical sounds of televisions, computers, game systems, radios and just normal conversation, and it may be unlikely that a siren could be heard indoors.”
Norman and Moore follow the same regional siren policy. A siren means "take cover." Norman and Moore do not sound an “all clear” siren, so any siren means “take cover,” even if it's the second or third siren of the day. Sirens sound for three minutes.
“The amount of lead time we get from the National Weather Service for the decision-making process is usually 10 to 15 minutes when they issue a tornado warning,” Grizzle said. If a siren is sounded too early, people may leave shelter before it is safe.
Tornado sirens are sounded in Norman and Moore when there is an “imminent direct threat.”
“We do not want to cry wolf,” Grizzle said.
• What determines whether sirens are sounded? “The direction and path of the storm determines which sirens are sounded. Where is the imminent threat?” Grizzle said. “You have to analyze that data, and you have to do it rapidly.”
When the decision is made to sound sirens, do they sound in all parts of Norman?
“We have the ability to zone the sirens,” Grizzle said. “We have preplanned all these zones. Predominantly, we have either an east zone or a west zone, with the dividing line being East 60th Avenue.”
Norman and Moore test sirens at noon every Saturday, except when the possibility of severe weather is present or when special events are planned.
Norman encourages sheltering in place rather than traveling a distance to a shelter. Usually moving to the lowest level of a home or office in an interior room with no windows, such as a closet or restroom, is the best idea if there isn't a nearby storm shelter.
“Sometimes people wait too late to go to a shelter and put their families at risk,” Grizzle said. “Sheltering in place is simply utilizing the shelter you're in and selecting the best place to shelter.”
People are encouraged to create a plan for taking shelter and stay weather aware on high-risk days.
“Too often, families wait for the outdoor warning sirens to sound before enacting their plan, but by then, it can be too late to properly react to conditions,” Norman Fire Chief and Emergency Manager Travis King said. “It is critically important for residents to have an emergency plan in place and to stay aware of changing weather.”
Most tornado deaths occur in cars and mobile homes. Moore recommends finding a substantial structure or designated tornado shelter, if possible.
“If in your car, remember that highway bridges are not designed as tornado shelters and make for very poor shelter,” according to the Moore website.
Residents who have shelters can register them to help emergency responders find them in the case the exit is covered by debris.