Sunday, August 18, 2013

Tornado Safety At School

11:40 AM Wednesday Update...  The 2013 summer contest is winding down.  As of August 20th, here are the numbers.  To check your entry, click on link in the navigation bar above.

Total number of degrees at Little Rock...7298

Total rain (LR and NLR)... 17.19''

There are so many things a parent worries about when it comes to their kids safety.   One of which I want to address in this post. 

Remember what happened on May 20th in Moore, Oklahoma?  Can you imagine knowing your kids school was destroyed by a tornado, you're miles away, roads are blocked, communication is down, and there's nothing you can do.  Knowing your school has a solid plan of action can help with some peace of mind.  In light of what happened at Plaza Towers Elementary (the school took a direct hit from an EF-5 tornado and 7 students were killed),  it's a good idea as a parent to make sure your school administrators review those emergency plans. Now is the time to reevaluate what schools do when tornado warnings are issued.

We often think severe weather season is only the spring, but that's not always true.  We have a secondary severe weather season in the fall and there have been times when it's worse compared to spring. 

I have found a number of resources I hope you read, watch, and pass along to your school administrators.  Let's learn from what happened in Oklahoma and do what we can to keep this from ever happening here. 

Here's some great information below from the NWS and I have some links below.

Some things to consider:
  • SECONDS COUNT. If it takes more than 2 or 3 minutes to move all upper-floor people down, things get really risky! Though the average lead (advance) time on tornado warnings has gone up a lot in recent years, remember that the average still includes some warnings with NO lead time, or just a minute or two. Warnings are not absolutely perfect, radars can't see everything, and tornadoes don't always touch down miles away and make themselves visible before hitting. Plan for a reasonable worst-case scenario -- a tornado is spotted very closeby, and hits with little or no warning. That way, during the majority of cases when there are warnings with several minutes of lead time, the plan can be executed and those people are all in a safe place within one or two minutes of the first alert. That is the ultimate goal. Now, how do you define a "safe place?" There is no guaranteed "safe place" in a tornado; but... 
  • FLYING DEBRIS is the biggest tornado hazard. That's why one needs to put as many walls as possible between oneself and the tornado. Are there interior hallways, rooms or corridors on the second floor which are NOT exposed to the outside through windows, doors or walls of glass? If not, then it can turn into a death trap of flying broken glass. If there are enough enclosed places on the second floor with no direct exposure to the exterior, perhaps you can save the time needed to move people down one floor. But even then...
  • BUILDING STRENGTH: Architecturally, how sound is the construction of the main building? What interior parts can stay intact during total structural loads created by 150-200 mph winds (which exceed the speeds found in most tornadoes) from any direction? Is anyplace on an upper floor safe enough in such structural stresses? To best answer that, consult a professional architectural engineer -- preferably one who has wind engineering experience. Sure, there are budgets to make; and such expertise won't come cheap -- but it can ultimately save lives. FEMA also has an online discussion on construction of community tornado shelters, including those for schools. Other valuable sources for help are your local emergency manager's office, and the Warning Coordination Meteorologist (WCM) at your nearest National Weather Service office.
  • NEW CONSTRUCTION: Although this guide is intended for existing facilities, many of the same concepts can be applied to making tornado-safe schools from the blueprint stage. The same questions about wind damage and tornado safety should be asked of the architects and engineers. Again, this is where a licensed engineer with wind engineering specialization would be the most beneficial; and the FEMA tornado shelter guides are great resources too. Even if hiring a professional engineer isn't an option, the builder can line with concrete enough interior rooms in the school to create a series of safe rooms to hold students. Safe rooms aren't just for houses! They can also be retrofitted into existing facilities; but that is usually much costlier than building them in new construction.
  • PORTABLE CLASSROOMS: These can be death traps. Portable classrooms are most often constructed like mobile homes; and they are just as dangerous. Any sound tornado safety plan must include getting students out of portable classrooms and into a safe area in the main building, as quickly as possible, to minimize the time spend outside and exposed to the elements. While the seconds spent outside will pose considerable risk, the danger inside the trailer is just as great. If feasible, students should be evacuated from portable classrooms before the storm threatens -- before the warning, when a tornado or severe thunderstorm watch is issued. Remember: Tornadoes can occur with little or no advance warning. Moving those students inside the main building for every SPC watch may be a hassle; but it may also save precious seconds and the lives of students if a tornado or extremely severe thunderstorm hits later.
  • DANGER - GYMS and AUDITORIUMS: Large, open-span areas, such as gymnasiums, auditoriums and most lunchrooms, can be very dangerous even in weak tornadoes, and should not be used for sheltering people. This sort of room has inherent structural weaknesses with lack of roof support, making them especially prone to collapse with weaker wind loading than more compact areas of the same school building. Consider the aerial photo of Caledonia (MS) High School (below) as an outstanding example of this, when the near side was hit by a tornado in January 2008. 


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