Oklahoma: May 2013 Archives
NWS JetStream - RIDGE Radar Downloads
How to download National Weather Service radar imagery, one layer and snapshot at a time. Explains file naming conventions and directory locations. (The nearest radar station to Tulsa is INX, just west of Inola on US 412.
Why There Was No Basement Tornado Shelter in That Oklahoma City School « LewRockwell.com Blog
"Politicians like himself will always spend taxpayers' money in a way that enhances THEIR popularity and maximizes THEIR chances for re-election. There are orders of magnitude more votes to be had in handing out welfare benefits or lavish public employee pensions than in replacing leaky water lines. Public employees are well organized politically; the average taxpaying citizens are not.... Putting a basement in a new school building will not motivate government school teachers to spend thousands of hours campaigning and driving voters to the polls in school buses. Promises of pay and pension increases will."
The writer has a point about politicians, but it doesn't apply to Oklahoma and the way we finance education and school facilities. School bond issues can only be used for capital improvements and equipment, not operating costs. If anything, school bond issue supporters here work for low voter turnout; I've never heard of driving people to the polls in school buses, which I'm pretty sure would be against the law. Heavy construction companies are usually very supportive of school bond issues, since they stand to win the contracts to do the work, and publicly-funded construction can take up the slack when the economy has stalled new commercial construction. There's plenty of political incentive to build school tornado shelters; I suspect the hindrance is practical. Oklahoma just doesn't have many basements. (Remember what happened to Tulsa's buried Belvedere.) Blair, Oklahoma, has an impressively large, partially buried storm shelter on its school playground, easily seen from US 283, about 20' wide by 70' long, built in 1928 after a tornado destroyed the school.
American Meteorology Society Journals Online - Tornado Damage Survey at Moore, Oklahoma
After the May 3, 1999, Moore / Midwest City tornado, the Wind Science and Engineering Research Center at Texas Tech University conducted a damage survey to determine the causes of structural failure. The team found that methods of construction -- joining roof to walls to slab -- permitted by code were inadequate to handle structural loads caused when the wind lifts up the roof. When a home is destroyed by a tornado, it becomes a collection of projectiles that the tornado can use to destroy the next house. Even if you build a sturdier house, it can be destroyed by the whirling remains of the shoddy home next door. The team was disappointed to learn that new houses being built after the tornado failed to incorporate improvements that would make the structures more resilient to high winds.
"Although it is true there are no provisions in building codes to construct houses to resist tornadoes, building codes are still important in mitigating tornado damage. A better-built house would yield less debris in a tornado, and occupants would have a better chance of surviving in such a house. In addition, structural improvements could reduce the level of damage to a house that experiences weaker tornadoes or straight-line thunderstorm winds that are just above code-required design levels and hence could mitigate economic loss and improve safety."
"As noted from our damage survey, numerous housing failures initiated with destruction of attached garages. In a typical case, garage doors blew in, allowing internal pressures to act in combination with external aerodynamic uplift pressures to remove the garage roof structure. Uplift on the roof structure caused toenailed connections in the wooden top plates to pull apart. Destruction of the attached garage frequently led to damage or the removal of the remaining roof structure on the residence."
"When the author visited the post-tornado reconstruction area, 6 of the 40 new houses contained tornado shelters or safe rooms; however, these homes generally were not built any better than prior to the tornado. Thus, homeowners appeared to be making the decision to provide for personal safety (i.e., building a safe room) instead of to increase housing strength (to provide property protection and increased safety). This decision may, in part, be based on the assumption that it is unreasonable or uneconomical to try to construct houses for the high wind speeds described on the F scale."
