Lessons From Moore
Remind me to never complain about a little cold or snow again.
Nothing like an EF-4 tornado hitting a major metropolitan area to put things into stark perspective.
In spite a warming Earth there's no conclusive, scientific evidence that we're seeing more violent tornadoes. There's more water vapor and instability to fuel severe storms, but in a warming world wind shear necessary for violent tornadoes should decrease over time. More research is needed, but I suspect the real culprit here is land use - suburban sprawl. The same monster tornado that hit farmland 20 years ago is now grinding into subdivisions and shopping malls.
Doppler radar can't always estimate the intensity of a developing tornado, and as a nation we suffer from tornado fatigue: too many warnings. Out of 10 tornado warnings only 3 will produce a tornado, and the ones that form are usually small and brief. This breeds apathy and cynicism, so when the big one, the nightmare ("Tornado Emergency") becomes reality - people are skeptical.
Review a Tornado Action Plan with your kids. Information is power.
A cool, wet Wednesday gives way to a partly sunny, lukewarm holiday weekend. As temperatures rise next week so will the risk of severe storms.
In the words of the Boy Scouts: "be prepared".
* photo credit above: "This Tuesday, May 21, 2013 aerial photo shows, from bottom to top, the path Monday's tornado took through Moore, Okla. The huge tornado roared through the Oklahoma City suburb Monday, flattening entire neighborhoods and destroying an elementary school with a direct blow as children and teachers huddled against winds." (AP Photo/Kim Johnson Flodin)
Note: As of 2:50 PM CDT, the NWS survey conducted by several teams has now rated the Newcastle-Moore tornado as EF-5. The damage survey teams have also determined that the tornado began 4.4 miles west of Newcastle and ended 4.8 miles east of Moore, yielding an approximate tornado path length of 17 miles. The preliminary maximum damage path width is 1.3 miles. Crews will continue to sort through damage for a final intensity rating. The latest Public Information Statement issued by the NWS Norman forecast office can be found here.
Further updates and more detailed information of the tornado damage areas will be released later today and Wednesday. Below is a map with the approximate damage path of the Newcastle-Moore-South OKC tornado."
- A rating of EF-5 has been given to the tornado that affected the Newcastle, south OKC, and Moore areas in McClain and Cleveland Counties.
- The tornado had.a path length of approximately 17 miles and was on the ground for approximately 40 minutes from 2:56 PM - 3.26 PM CDT.
- The preliminary maximum path width is 1.3 miles.
* Death toll stands at 24, although I expect this to go up as recovery efforts continue today. Hundreds are injured; many residents still missing. As many as 20,000 residents of Moore are homeless.
* 30 square miles impacted by moderate to extensive tornado damage.
* This may top Joplin as the most expensive tornado in U.S. history. The May, 2011 Joplin tornado came in at $2.8 billion. I expect the 2013 Moore tornado to be comparable, probably $2-3 billion in total damage. There's a good chance this will be America's most expensive tornado on record.
* before the tornado hit several Oklahoma City TV meteorologists encouraged people in the direct path of this tornado to "drive away". The reality: if an EF-4 strength tornado is approaching and you don't have a basement or shelter your odds of survival are small. Statistically it's better to get into your vehicle and try to outrun the tornado. The problem: as good as Doppler radar is it can be difficult estimating the intensity of a tornado, even 10-15 minutes in advance. We can see rotation, even a hook echo, but is it an EF-1 or a monster EF-5? Unlike hurricanes, where we can see satellite imagery and estimate strength, tornadoes are much more difficult to predict in advance: track and ultimate intensity.
* there is no evidence that we're seeing more EF-4 or EF-5 tornadoes, which comprise less than 1-2% of ALL tornadoes that strike the USA. A warmer atmosphere increases instability and buoyancy, but wind shear in a warming world should decrease over time. More research is needed, but we can't (yet) connect the dots and claim that there is causal connection. More research is needed.
Summary: It's our worst fear as meteorologists: a large (urban) tornado. One glaring problem: "tornado fatigue". As a nation we are still issuing too many tornado warnings (at least that's the consensus among most private meteorologists I know). Nobody wants to miss a tornado - that's the cardinal sin, so NWS issues warnings on just about every rotating thunderstorm they find on Doppler. The FAR or false alarm rate is still hovering near 70%. Stated differently, 7 in 10 tornado warnings produce NO tornado. This leads to apathy ("they're crying wolf!") and when the big tornado does materalize, when our worst fears are realized, many residents simply aren't ready to take the measures necessary to protect their lives.
In a hurricane you have days to prepare; a tornado: 5-30 minutes. The average lead time, nationally, is 13-15 minutes. Last year I proposed new terminnology, leveraging "Alerts" (for rotation based storms) and "Tornado Emergencies" (for confirmed tornadoes on the ground moving into urban areas). This is a reflection of land-use trends and suburban sprawl. Tornadoes that would have hit farmland 10-30 years ago are now hitting subdivisions. As metropolitan areas expand the probability of a direct strike from major tornadoes goes up steadily over time. Last year I wrote an article for Huffington Post, recounting a severe storm conference, where a well-respected structural engineer/meteorologist predicted that, within our lifetime, a single U.S. tornado will hit an urban area, even a downtown, with over 1,000 fatalities from a single twister. Yesterday was a reminder (to me) that his prediction may not be as far-fetched as it sounds. It's land-use, statistics and probabilities, another unpleasant symptom of expanding metropolitan areas.
Photo credit above: "The rubble of a destroyed neighborhood lay mixed together where it fell Tuesday, May 21, 2013 a day after a tornado moved through Moore, Okla. The huge tornado roared through the Oklahoma City suburb Monday, flattening entire neighborhoods and destroying an elementary school with a direct blow as children and teachers huddled against winds." (AP Photo/Brennan Linsley)
Image credit: this frame-grab from the 1986 Brooklyn Park, Springbrook Nature Center tornado courtesy of KARE-11 and tcmedia.com.