What is NSSL?

• Established in 1964

• One of 12 research laboratories in NOAA

• Only federal lab focused on severe-weather research

• Employs 140 people in Norman, Oklahoma

• Located on North Campus at Westheimer Airport

• $15 million a year ($5.5 million in NOAA base)

NSSL Accomplishments

• Engineering and scientific research that demonstrated the importance of the nationwide WSR-88D radar network

• Continued Doppler-radar research: dual-polarimetry, phased-array

• Severe-storm structure and dynamics• VORTEX field program (tornadogenesis)• Information and decision support systems• Collocation and interaction with Storm Prediction Center

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1074

7339

2

59

56

118

87

ApplicationsApplications

UnderstandUnderstandSevereSevereWeatherWeatherProcessesProcesses

ModelingModelingStudiesStudies

ObservationalObservationalStudiesStudies

To work in partnership with the National Weather Service to enhance NOAA’s capability of providing accurate forecasts and warnings of all types of hazardous weather events (blizzards, ice storms, flash floods, tornadoes, lightning, etc.).

The NSSL Mission:The NSSL Mission:

NOAANOAAServicesServices

TheoreticalTheoreticalStudiesStudies

What Do I Do at NSSL?• Midlatitude cyclones and fronts• Improving snow & drizzle forecasting• Arizona summertime convective-storm climatology (with

Pam MacKeen)• The Intermountain Precipitation

Experiment (with Univ. of Utah)• 3 May 1999 Oklahoma tornadoes

(with Paul Roebber, UW Milwaukee) • Research Experience for

Undergraduates mentor• Adjunct Professor, Univ. of Oklahoma• 2002 Winter Olympics, NWS Forecaster• Canoe & Kayak columnist

Lightning and Lightning Safety

Ron HolleVaisala - Global AtmosphericsTucson, Arizonarholle@glatmos.com

David SchultzNOAA/National Severe Storms LaboratoryNorman, Oklahomaschultz@nssl.noaa.gov

The Lightning Hazard

• An average of 25,000,000 cloud-to-ground flashes strike the ground each year in the U.S.

• Lightning strikes the ground nearly everywhere

• As a result, specific warnings cannot be issued for every flash for each person.

stormshot.comIvan Eberle

Average Annual Storm-Related Deaths from 1966 to 1995

Floods Lightning Tornadoes Hurricanes0

50

100

150135

8573

25

Lightning Casualties by Statefrom 1959 to 1994

498

732

394

577

629

644

473

545

410

1523

A

Rank 1-1011-2021-3031-52

331 355

347296 295

306

278

360

355

250

40

26

1879

64

87

116

164

104

249

79

35

111

169 241

234 176

227

238

235

18542

8849

12630

76

108

Hawaii: 4

Alaska: 0

D. C.: 23 Puerto Rico: 36

Casualties

Lightning Casualty Rate by State from 1959 to 1994

Rank 1-10

11-20

21-3031-52B

Casualty rate

Settings of U.S. LightningDeaths 100 Years Apart

1890s Indoors most often - 23% of all deaths inside homes Next largest - outdoors and agriculture Almost no recreation and sports deaths

1990s Agriculture - much less frequent Only 2% inside houses Outdoors is largest category - employment, around

homes, other urban activities 12% of deaths under trees Sports and recreation deaths frequent - beach, water, golf, camping

Lightning Casualties by Gender

0

10

20

30

40

50

60

70

80

90

Male Female

Colorado Central Florida

Odds of Being a Lightning Victim

• 280,000,000 people in U.S.• 60 killed, 340 injured a year (official)

1 in 700,000 • 100 deaths and 900 injuries a year (likely)

1 in 280,000• Life span of 80 years 1 in 3,500• Major impact on 10 people 1 in 350

• Temperature– 50,000°F

• Power– 10,000 MegaWatts for 1/2 second

• Energy– 30,000,000 Volts

– 50,000 Amperes

• Size– 1 inch

Lightning

Necessary Conditions for Lightning Formation

• Updraft in a cumulus cloud

• Colder than freezing at top

• A mixed-phase environment with: Graupel–soft irregular hail particles Ice crystals Supercooled liquid water

Earle WiIliams, MIT, 09/98

Cumulus Towers

Ronald L. Holle©1990

Lightning

• Lightning is an electric discharge in the cloud.• Most lightning paths remain within the cloud;

others are cloud-to-ground.• From the initiation point (around 15,000 feet

during summer), the stroke travels in 50-yard steps until it reaches the ground.

• At the lower tip of each step, the leader hesitates, looking for something to strike within about 50 yards.

Streamers

• At the ground, there are small (inches to feet long) streamers reaching upward to the electrified cloud.

• When the downward leader connects to an upward streamer, the bright light called lightning is visible and moves upward.

• Charge is lowered to the ground, but current flows upward.

• Most clouds lower negative charge to the ground, but 5% lower positive charge.

Why Trees and Fences are Bad Places

Ruth Lyon-Batemen, Island Park, Idaho

When Lightning is Imminent

• hair stands on end• sparks, electrical discharges• St. Elmo’s fire• hear static discharges

8/20/75: Sequoia National Park at Moro Rock: One person killed and 8 injured, the most seriously, the photographer. All were from an extended family. Hail was falling as they were at the top, 300 feet higher and 1/3 mile away from the parking lot.

Flash-to-bang

Storm motion

5 sec. 10 sec. 15 sec..

1 mile 2 miles 3 miles

.

Flash Outside Rain Shaft

Blue Sky

• Part of the sky is often blue during lightning.

• Summer thunderstorms are vertical.

• Thunderstorms often are isolated.

• About 10% of lightning occurs without rain at the strike point.

• Pay attention to the thunder, not the blue sky or rain.

Visible Sky DuringLightning Threat

Lightning was observedfrom the dark cloudoverhead within a fewminutes of this view

Boulder, Colorado24 August 19911119 MDTToward S

Ronald L. Holle©1991

Visible Sky DuringLightning Threat

Lightning was observed 2 miles away 10 seconds before photo

Tucson, Arizona19 October 20001305 MSTToward S

Ronald L. Holle©2000

Sequence of Cloud-to-Ground Flashes in Colorado Storm

225

230

235

240

245

470 475 480 485 490 495

North-Southdistance(km)

East -West d ist ance (km)

Clust er No. 7Nort heast Colorado

Last

First

Successive flashesare within 15 kmand 5 minutes of theprevious flash

The 30–30 Rule

Most people who die from lightning are struck early in the storm or near the end.

80% of the cloud-to-ground flashes within the same storm fall within 6 miles (10 km) of the previous ground strike point. 5 seconds times 6 miles = 30 seconds

93% of successive cloud-to-ground strokes are within 5 minutes of each other, but the distribution extends out in time with quite a few lightning casualties at longer times. So, we advocate 30 minutes after the last stroke before continuing outdoor activities.

Lightning Safety Precautions

1. Avoid dangerous lightning situations

• Watch for signs of a thunderstorm that is starting to grow quickly

• Be aware of other storms in your area

• Give yourself time to reach a safe place

before lightning is an immediate threat

Lightning Safety Precautions

2. Plan Ahead

Designate a spotter who is watching for the threat of lightning

Watch for storms growing quickly before

it's too late to reach a safe place

Follow your safety plan

Lightning Safety Precautions

3. Safe places

Residence or frequently occupied building

Avoid contact with electric lines, phone lines, and plumbing. Unplug appliances before lightning arrives

Vehicle with a metal top

Avoid contact with metal parts, and antenna connections

Lightning Safety Precautions

4. Unsafe places

Shelters

Rain, sun, beach, golf, or picnic shelters

Tents

Open areas more than 100 yards across

Trees, poles, tall objects

Lightning Safety Precautions

5. Don’t be the highest object, or

connected to it

• Don't be the highest object

• Don't be connected to anything taller than its surroundings

• AS A LAST RESORT: Crouch on the balls of the feet, head down, and cover your ears with your hands.

6. Use the 30–30 rule

First 30 30 seconds = flash-to-bang before storm

Second 30 Wait 30 minutes after last flash or thunder before resuming activity

Especially critical for large groups

Lightning Safety Precautions

Lightning Safety for Groups

Virginia Tech vs. Georgia Tech(Aug. 27, 2000)

Lee Trevino, Jerry Heard and Bobby Nichols were struck by lightning during the 1975 Western Open. The incident prompted newsafety standards in weather preparedness at PGA events, but four spectators were killed when struck by lightning during the 1991 U.S. Open at Hazeltine National.

7. Special Outdoor Advice

• NO PLACE OUTSIDE IS SAFE DURING THUNDERSTORMS!

• Be off the mountains by the time afternoon thunderstorms are expected.

• Trails within the forest are only marginally safer than exposed trails.

• Remove backpacks to expedite getting to safety.

• Caves, overhangs, and pavilions only protect you from the rain, not the lightning, which can travel from the strike point to you.

Lightning Safety Precautions

When on the Water

• Get to land immediately.• Lightning strikes have killed or injured people

more than 30 yards away on water.

wildweather.com

Lightning Effects on People

• Deaths (10% of the time)The only cause is cardiopulmonary arrest

• Injuries

52% - Memory deficit

44% - Attention deficit

41% - Sleep disturbance

38% - Dizziness

. . .

Dr. Mary Ann Cooper, April 1999

First Aid for Lightning Victims

• Call 911.

• Make no more casualties by exposing rescuers to continuing lightning danger.

• It is safe to handle a lightning victim.

• Check for breathing and pulse–administer CPR and/or mouth-to-mouth resuscitation, if necessary.

• Check for other injuries: fractures, lightning entry and exit points (e.g., fingers, toes, belt buckles, jewelry).

• Do not move victims with suspected spinal injuries.

• Prevent patient from going into shock (cover with blanket, keep dry, do not let victim walk around).

• Take even stunned or otherwise unhurt victims to hospital for proper medical attention.

http://www.nws.noaa.gov/nwr

NOAA Weather Radio

Resources

NOAA/National Severe Storms Laboratoryhttp://www.nssl.noaa.gov/mag

NOAA/National Weather Servicehttp://www.lightningsafety.noaa.gov

Cloud Flash

White Lightning Symbols Are 4 Cloud-to-ground Flashes In Spider Flash on LDAR II - 17 August 2001 at 1515:38 UTC

Injury

START

END

Cloud-to-ground Lightning BeforeNearby Cloud-to-ground Strokes

Probability of Detection False Failure

Lead Time in Minutes Alarms to Warn

3 10

4 miles 58% 26% 43% 30%

6 miles 76% 60% 57% 17%

8 miles 85% 75% 63% 11%

10 miles 89% 81% 69% 9%

Warningradius

Time Lags Minutes Since Last Probability of Ground

Ground Stroke Stroke Within 2 Miles

0 100%

5 7%

10 4%

15 1%

20 0.8%

25 0.6%

30 0.5%

Responses to Lightning Injury

• Denial• Isolation• Self-medication by drugs and alcohol• Anger at family, professionals, others• Blame• Different person• Disappointment• Acceptance - Final stage

Dr. Mary Ann Cooper, April 1999