The National Weather Service’s Storm Prediction Center (SPC) couldn’t have done a better job identifying in advance the Arkansas zone where devastating tornadoes claimed at least 10 lives along a 80-mile path of destruction. The precision-forecasting and efforts to warn undoubtedly saved many lives, but the gut-wrenching toll proves our best science only goes so far.
One full day in advance of the massive tornado, SPC’s suite of high resolution forecast models (or “ensemble of opportunity” shown above) pinpointed – with amazing precision – the zone most at risk of rotating storms (see above). On Sunday morning, SPC declared this zone under a “moderate” or “high” risk of severe thunderstorms and issued timely watches and warnings.
Zones of severe storm risk identified hours (and days) in advance
HIGH Risk of severe storms tonight includes Little Rock, ARK. Strong, long-tracked tornadoes possible. pic.twitter.com/kIzg47DHbs— SevereStudios (@severestudios) April 27, 2014
“Particularly dangerous situation” tornado watch issued in the afternoon
MAP: Here’s the PDS (Particularly Dangerous Situation) Tornado Watch. Consider this the most serious situation. pic.twitter.com/hvdSPN4akc— SevereStudios (@severestudios) April 27, 2014
“Tornado emergency” warning issued
But humans only have so many defenses against a half-mile wide vortex of destruction, with textbook radar and satellite presentation:
Pictures and video from Twitter show very wide tornado on the ground
Radar imagery shows tight velocity “couplet” where green indicates strong winds blowing towards radar and, immediately adjacent, red indicates strong winds blowing away from it: this signifies very strong rotation in the thunderstorm
Satellite image shows explosive convection or “bubbling” signature, indicative of vigorous vertical motions
Three-dimensional view of storm shows cloud tops extending above 30,000 feet
At least two tornadoes touched down along an 80 mile path
The images of the aftermath, especially around Mayflower and Vilonia, are heart-breaking:
The damage in mayflower is horrible pic.twitter.com/5wi76co8mg— Garrett Johnson (@Garrett_J19) April 28, 2014
How strong were these tornadic winds? Three big RVs wrapped around a twisted I-40 billboard in Mayflower, AR. pic.twitter.com/5Rx5fPuW9k— Mike Seidel (@mikeseidel) April 28, 2014
When tornadoes this intense strike populated areas, the only safe place may well be underground or in a hardened safe room. Meteorologists continue to work with social scientists to develop strategies that will motivate people to develop and/or seek appropriate shelter in dangerous tornado situations. Increasingly, tornado predictions are accurate (the physical science), but our preparedness efforts, involving more social science and the psychology of how people make decisions, are not completely adequate.