• Hurricanes Harvey and Irma• Storm chasing goals and

motivations• Dominator storm chasing vehicles• Storm chasing field research• New tornado/hurricane probe• Video from inside a tornado• New 2017 tornado footage• Suction vortices

Video

The Science

of

Storm Chasing

2012 DEN Summer InstituteJuly 21-25; Missoula, MT

Extreme Storm Chasing

Discovery 2008 Season Trailer: Play

Storm Chasing Vehicles 1999-present

1996-1999 2003-2004

D2 (2011-present) D3 (2013) D1 (2009-present)Mythbusters aircraft test: Play

May 3, 1999 storm chase: Play

2018 Science Mission

Suction Vortices!

• Form near the ground

• As small as a few

meters in diameter

• Up to 5 simultaneous

• Friction inducedFiedler (2009)

• Wind speed 2 to 4

times parent vortex

• 500-600 mph???

Suction vortex video: Play

Fiedler (2009)

Storm Chasing Motivations1. Storm reporting

– HUGE Social media and mobile applications– Traditional Cell phone and radio communication– Coverage for Accuweather

2. Disaster response– Storm chase ends if damage is encountered– Emergency response and first aid training is critical

3. Data Collection– Measuring wind speed/direction, pressure, temperature

inside tornadoes, hurricane eye walls – Measure horizontal and vertical winds inside tornadoes

near ground-level– Measure temperature, moisture, and pressure within

the funnel with meteorological parachute probes (air cannons, RC Plane)

Hurricane Harvey• Landfall as category 4 hurricane in Aransas Pass to Rockport to Holiday

Beach, TX• 130 mph maximum sustained winds at landfall• Dropped over 50 inches of rain across parts of East Texas including Houston

area as greatest storm total in recorded U.S. history

2012 DEN Summer InstituteJuly 21-25; Missoula, MT

Extreme Storm Chasing

Hurricane Harvey eye wall, Rockport, TX: Play

Hurricane Harvey Probe Data

Hurricane IrmaHurricane Irma Key West to Key Largo, FL: Play

Hurricane Irma

• Powerful Cape Verde type hurricane• Strongest Atlantic basin hurricane ever recorded (wind) with 185 mph winds• Minimum pressure dropped to 914 mb• Devastated northern Leeward Islands of Barbuda, Anguilla, Saint

Martin/Maarten, British Virgin Islands, Turks and Caicos, northern Cuba, and finally Florida.

• At least 79 fatalities

Helical Suction Vortices ~ Tornado DNA

Fiedler (2008)

The TVN DominatorThe Ultimate Tornado Research Machine

Dominator!

May 22, 2010 Bowdle, SD wedge video: Play

2009 DOMINATOR 1 (D1)Extreme Tornado Research Vehicle

*138.8 mph wind recorded!

June 17, 2009 TVN window blowout: Play

• Hydraulic shell lowering system• Only 16-gauge steel armor• Manual Lexan window-lift system• Vulnerable from tail wind• Single windshield wiper system = fog-up• Roof-mounted Lexan dome for HD camera

D1 Specs::

2011 DOMINATOR 2

May 24, 2011 Canton, OK EF3 tornado: Play

• Longer/wider shell, lower deployment height• Hydraulic spikes• Automatic Lexan window lift system• Internal air cannon system• Triple wind shield wiper system• Upgraded research equipment

D2 Upgrades::

2013 DOMINATOR 3• 10,500 lb. total weight• Base vehicle Ford F350 • Power Stroke Diesel V8• 780 high carbon steel reinforced with 4 layers

of laminated Kevlar on “gull wing” doors. • Kelderman airbag suspension with computer

regulated ride height system.

D3 Features:::

July 27, 2015 Tipton, MB tornado: Play

Mobile Doppler Radar• Mounted on roof Dominator 1 and 2

• Intended to measure vertical winds inside tornadoes

• Low-power (750 W max power), 2 phased array antennas

• 2.9 cm wavelength, X-band 10.4-10.45 GHz frequencies

• Measured 175 mph updraft in June 17, 2010 EF4 tornado

• Upgrade featured pulse capability to measure wind vs. height

Version 1.0 (2009)

Version 2.0 (2011)

RC Tornado DronesModel rocket & Launcher Quad Copter Drone

RC Vehicle Drone

VIDEO: Rocket deploymentVIDEO: RC plane

Ground-based Tornado Probes

Video: Play

Video: Play

Zorb Probe

Ground-based Probe

June 17, 2010 Tornado Intercept• June 17, 2010 Northern Plains

tornado outbreak• EF4 tornado, 1-mile wide• Sadly, two fatalities were reported

from these tornadoes• ~200 mph updraft measured• Anemometer ripped off by debris!!!

Event Overview

Mobile Radar Data:

Aurora, NE Tornado Intercept

138.8 mph!

Northwesterly wind in west side of

tornado rapidly decreasing as

circulation moves eastward

8 mph minimum wind speed

in the center of the tornado

with rapid reversal in wind

direction

BLUE = Wind Speed

RED = Wind Direction (front of

vehicle pointing at 0 degrees)

facing east on W-E road

Mother’s Day 2015Video: Play

Statistics• 2 mi. N Wray, CO to 10 mi. NNE Wray• Time: 5:51 pm – 6:16 pm MDT• EF rating: EF2• Est. peak winds: 130 mph• Path length: 8 miles• Max width: 440 yards

May 7, 2016; Eastern ColoradoWray, CO tornado from close-range

Raw video: Play

Statistics• E of Ensign, KS to just SW of Dodge City • Time: 6:13 pm – 6:40 pm CDT• EF rating: EF1• Est. peak winds: 100 mph• Path length: 4.8 miles• Max width: 150 yards

May 24, 2016 OutbreakTornado #2

Video 1: Play

GoPro time-lapse: Play

Statistics• Just N of Minneola, KS to NE of Ensign, KS• Time: 5:53 pm – 6:25 pm CDT• EF rating: EF3• Est. peak winds: 136 mph• Path length: 11.94 miles• Max width: 300 yards

May 24, 2016 OutbreakTornado #1

Video 1: Play

April 27, 2011 Tornado OutbreakSoutheast U.S.

• NOAA estimates 211 tornadoes

• 3 EF5 tornadoes

• Most tornadoes in 24-hour period in U.S. history

• Next most was 148 on April 3-4, 1974

• 309 fatalities

• Hackleburg (78) and Tuscaloosa (61) tornadoes deadliest since 1955 to date

Philadelphia EF5: Play

South Dakota Tornado FestJune 24, 2003

• Over 50 tornadoes reported on this day!

• ½ mile wide F4 wedge tornado

• Three tornadoes on the ground at the same time with this supercell.

• Tornado moved at 15 mph, allowing for incredible photo opportunities.

• The town of Manchester, SD sustained a direct hit, but thankfully no fatalities occurred.

VIDEO: Play

DAMAGING HAIL!VIDEO: Hail

Manitoba, Canada Wedge! June 23, 2007

• Violent F3-F4 tornado

• Bright white tornado from unique sun angle

• Storm chase vehicle: Hyundai Accent with a max speed of 60 mph!

• Softball size hail cracked the wind shield after tornado passed.

• Canada is new territory for storm chasers (season: Late June through early Aug)

VIDEO: Canada

DOMINATE the Storm!