Atmospheric Electricity ‐ Lightning Threats Safety Preparedness for Outdoor Venues
Frank McCathran, Director, Enterprise Solutions Session Objectives
At the end of this session participants will be able to:
• Discuss the truths and myths about lightning • Explain the basics of lightning and thunderstorm development. • Explain what to do when caught in a storm and safety procedures if someone is struck by lightning. • Understand new advancements in lightning and severe weather detection and advanced warning. Does your facility currently have a lightning and severe weather policy? Does your facility currently have a lightning alerting system? My facility relies on the following when threatened by lightning: If you have a lightning alerting system now, how satisfied are you with it? Lightning Truths, Myths, and Tips Lightning Truths
More than 400 people are struck by lightning each year in the U.S.
On average 55‐60 people are killed. Hundreds per year are left with permanent disabilities. Odds of being struck in your lifetime is one in 3,000. Lightning is second leading killer of storm related hazards. Lightning Truths • Lightning bolts are approximately the size of a quarter in diameter.
• Lightning strikes the earth roughly 100 times per second.
• Lightning can typically be 5 miles in length.
• Lightning strikes are 5 times hotter than the surface of the sun (50,000 degrees vs. 10,000 degrees). Lightning Myths & Facts
MYTH: Lightning Never Strikes The Same Place Twice. FACT: Lightning often strikes the same place repeatedly, especially if it’s a tall pointy isolated object.
MYTH: If It’s Not Raining, Or If Clouds Aren’t Overhead, I’m Safe From Lightning. FACT : Lightning can strike more than 10 miles from the thunderstorm, far outside the rain or even thunderstorm cloud.
MYTH: Rubber Tires Protect You From Lightning In A Car By Insulating You From The Ground. FACT : Lightning laughs at two inches of rubber! Most cars are reasonably safe from lightning. But it’s the metal roof and metal sides that protect you, not the rubber tires.
10 Lightning Myths & Facts
MYTH: A Lightning Victim Is Electrified. If You Touch Them, You’ll Be Electrocuted. FACT: The human body doesn’t store electricity. It is perfectly safe to touch a lightning victim to give them first aid.
MYTH: If Outside In A Thunderstorm, Go Under A Tree To Stay Dry. FACT: Being underneath trees is the second leading activity for lightning casualties.
MYTH: I’m In A House, I’m Safe From Lightning. FACT : While a house is a good place for lightning safety, just going inside isn’t enough. Lightning Myths & Facts
MYTH: Structures With Metal, Or Metal On The Body (Jewelry, Watches, Glasses, Backpacks, Etc.), Attract Lightning. FACT: Height, pointy shape, and isolation are the dominant factors controlling where a lightning bolt will strike. The presence of metal makes virtually no difference on where lightning strikes.
MYTH: If Trapped Outside And Lightning Is About To Strike, Lie Flat On The Ground. FACT: This advice is decades out of date. Better advice is to run for a safe structure.
MYTH: That’s Not Dangerous, It’s Just Heat Lightning. Fact: Lightning is lightning and you need to take notice and possibly precautions. Lightning Safety Tips
NO PLACE outside is safe when thunderstorms are in the area!!
• If you hear thunder, lightning is close enough to strike you. • When you hear thunder, immediately move to safe shelter. • Safe shelter is a substantial building or inside an enclosed, metal‐topped vehicle. • Stay in safe shelter at least 30 minutes after you hear the last clap. Lightning Safety Tips Indoor Lightning Safety Tips
• Stay off corded phones, computers and other electrical equipment that put you in direct contact with electricity. • Avoid plumbing, including sinks, baths, and faucets. • Stay away from windows and doors, and stay off porches. • Do not lie on concrete floors, and do not lean against concrete walls. Lightning Safety Tips Last Resort ‐ Outdoor Risk Reduction Tips
If you are caught outside with no safe shelter anywhere nearby the following actions may reduce your risk:
• Immediately get off elevated areas such as hills, mountain ridges or peaks • NEVER lie flat on the ground • NEVER use a tree for shelter • NEVER use a cliff or rocky overhang for shelter • Immediately get out and away from ponds, lakes and other bodies of water • Stay away from objects that conduct electricity (barbed wire fences, power lines, windmills, etc.) Lightning Safety Tips
If Someone Is Struck by Lightning
• Victims do not carry an electrical charge and may need immediate medical attention.
• Give first aid. Do not delay CPR if the person is unresponsive or not breathing. Use an Automatic External Defibrillator if one is available.
• Call 911 for help.
• If possible, move the victim to a safer place. Lightning can strike twice. Don’t become a victim. Types of Lightning Types of Lightning
Lightning An atmospheric discharge of electricity when positively- charged particles in one area meet negatively-charged particles in another area.
Cloud-to-Ground (CG) Lightning Lightning that extends from the cloud to the ground. Types of Lightning
In-Cloud (IC) Lightning Lightning that does not make contact with ground; sometimes referred to as intra-cloud and inter-cloud lightning.
Bolt From the Blue Courtesy NOAA A cloud-to-ground lightning flash which typically comes from the back or front side of the thunderstorm cloud, travels a relatively large distance in clear air away from the storm cloud, and then angles down and strikes the ground.
Courtesy NOAA Types of Lightning
Flash The complete bolt of lightning including the many forked tentacles called strokes/pulses.
Stroke/Pulse One of the many tentacles that comes out from a lightning flash. Many strokes/pulses make up the composite flash. Types of Lightning Systems Handheld Lightning “Detectors” Claim to detect lightning strikes in area and direction of storm.
• Least expensive • Very short range of coverage; • No logical or scientific basis for these units to be able to provide distance or direction. • No scientific validity.
“Beware especially of hand-held detectors’ reliability.” (National Lightning Safety Institute)
“Handheld lightning detectors are available from numerous manufacturers, but the performance of these handheld devices has not been independently verified, and they should not be used as the sole source for determining when to move to a safe location.” (National Athletic Trainers’ Association, Lightning Safety Position Statement, 2013) Lightning “Prediction” Systems Measures electrostatic field (static energy) in the atmosphere. Via calculations, a “prediction” is made for lightning potential.
• Most used in sports & recreation properties; • Very short range of coverage; • Sensitive to space charges not related to severe storms; • Threshold often set high to avoid false alarms, which can result in missed events. • No scientific validity. “Vendors who claim to ‘predict’ lightning in advance (which is impossible; it’s just guesswork) should be rejected.” (National Lightning Safety Institute) Lightning Detection Systems – Single Node
• Ground-based are most common; • Variety of types and methods; including ground-, aircraft-, and space-based; • Traditional single node systems underestimate lightning due to lack of… – Redundancy; and – Ability to only measure cloud- to-ground strikes. Lightning Detection Systems – Networks A network of integrated cloud-to-ground AND in-cloud lightning detection sensors.
• Leverages other detection sensors in network to better pinpoint location and time accuracy; • Detection of CG lightning improved due to redundancy • Traditionally only measures and maps cloud-to-ground strikes. Storm and Lightning Development
Real World Case Studies Near Miss at Texas Rangers Ballpark
41 July 8, 2012 ‐ Texas Rangers’ Game
6:43pm CDT First strike detected within the 10 Mile Radius July 8, 2012 ‐ Texas Rangers’ Game
6:56pm CDT – Lightning moves within 5.5 miles of the stadium July 8, 2012 ‐ Texas Rangers’ Game
6:57pm CDT –there is a pulse/flash just .5 miles from the stadium –5 miles closer than the previous “closest strike” July 8, 2012 ‐ Texas Rangers’ Game
7:10pm CDT –The likely “culprit” CG flash occurred just .09 miles from the pitchers mound. IC flash occurred at the same time just to the south of the stadium. July 8, 2012 ‐ Texas Rangers’ Game
Total strikes within 5 miles of the stadium (5 and 10 mile rings). Case Study in Lightning Safety When Every Minute Counts
4:17:50 PM –First IC Lightning Strike entered a dangerous range (10 mile ring pictured). Case Study in Lightning Safety When Every Minute Counts
4:51:21 – 5:02:29 PM –Both In‐Cloud & Cloud‐to‐Ground (total lightning) strikes surround the raceway property. 10 People Impacted. Case Study in Lightning Safety When Every Minute Counts
4:51:21 – 5:02:29 PM –In‐Cloud & Cloud‐to‐Ground lightning surround the raceway property. Case Study in Lightning Safety When Every Minute Counts
August 5, 2012 Pocono Raceway, Long Pond, Pennsylvania
Series of Events
3:40:00 PM ‐ NWS Severe Thunderstorm Watch issued 4:01:00 PM ‐ First In‐Cloud lightning strike detected within 20 Miles 4:12:00 PM ‐ NWS Severe Thunderstorm Warning issued 4:12:51 PM ‐ First In‐Cloud AND Cloud‐to‐Ground lightning detected within 15 Miles 4:17:50 PM ‐ First In‐Cloud lightning strike detected within 10 Miles 4:50:00 PM ‐ Race was called. Cars off track. 4:51:21 PM ‐ Cloud to Ground strikes within a mile of the property 4:52:34 PM ‐ Cloud to Ground strikes within a mile of the property 4:53:22 PM ‐ Cloud to Ground strikes within a mile of the property 4:54:54 PM ‐ Cloud to Ground strikes impact the property 5:02:29 PM ‐ Cloud to Ground strikes within a mile of the property Scientific Conclusions
• Severe thunderstorms contain high ICs, but may or may not contain high CGs. • Therefore, to provide total protection and increase warning times one needs to detect both CG and IC accurately. • Detecting both CG and IC (i.e. total lightning), tracks and predicts path of severe storms – provide much more weather safety intelligence (i.e. tornadic activity, downbursts, hail, flash flooding). Embracing Lightning Safety
Documented Policy Documented Policy System/Methodology System/Methodology Thank You! Questions/Comments
Frank McCathran Director, Enterprise Solutions Earth Networks – WeatherBug 800.544.4429, Ext. 4122 301.250.4122 Office 301.437.7096 Mobile [email protected] Indiana State Fair Stage Collapse – 8/13/11
NWS SPC Outlook issued 12:15 p.m. EDT
54 Chronology of Indianapolis State Fair Event
5:57PM NWS issues Severe T‐Storm Watch until 1a Sunday for Marion County, site of the Fair
7:32PM Line of storm enters Indiana with high flash rate, Dangerous Thunderstorm Alerts (DTAs), and NWS warnings
8:09PM 42 mph wind gust reported at Earth Networks station in Crawfordsville, IN
8:16PM 56 mph wind gust reported at Earth Networks station in Roachdale, IN (35 miles from Fairgrounds)
8:30PM Earth Networks issues DTA for Marion county, IN just west of Fairgrounds for storm with 75 flashes/min.
8:39PM NWS issues Severe Thunderstorm Warning for Fairgrounds
8:41PM Wind gust 45 mph at Eagle Creek Airpark (8 miles due west Fairgrounds)
+/‐8:45PM State Police issue warning to crowd, but many do not leave
8:49PM Wind gust of 70 mph was recorded at the Speedway in Marion Co., by long‐time TV weather spotter. About 8 miles WSW of Fairgrounds
8:50PM Earth Networks issues DTA for Fairgrounds
8:50‐8:55PM Stage collapses at Fair from wind gusts, 6 killed, 44 injured; wind estimated 60‐70 mph
8:56PM Gust 53 mph at Lucas Oil Stadium, 5 miles SSW of Fairgrounds
55 NWS Indianapolis Doppler Radar winds
56 Standard Reflectivity from NWS Indianapolis
Time 8:44 pm EDT, about 7 minutes before the collapse
Red “x” is the Fairgrounds. Arrows shows wind gust front is miles ahead of actual thunder‐ storm rain.
57 Standard Reflectivity from NWS Indianapolis
Time 8:48 pm EDT, just a couple minutes before the collapse
Red “x” is the Fairgrounds.
Arrows shows wind gust front is miles ahead of actual thunder‐ storm rain.
58 Wind Gusts From Mesonet
59 Lessons Learned – Indianapolis State Fair
‐ Dense mesonet wind data can alert forecasters and emergency managers to potentially damaging, localized wind gusts and other threatening mesoscale phenomena.
‐ WeatherBug lightning data and automated DTAs can be a powerful tool for forecasters in a severe weather episode.
‐ Storms can rapidly intensify, as seen in the flash rate of this lightning cell which ramped up significantly at 8:47p from 10 flashes/min to 40 flashes/min at 8:54p, around the time when the stage collapse occurred.
‐ New storm development can occur on the outflow of parent storms, again highlighting the value of a dense mesonet.
Courtesy: Getty Images Case Study in Lightning Safety Dangerous Thunderstorm Alerts Midwest Severe Outbreak, Feb. 28‐29, 2012