October 2010 Arizona tornado outbreak

On October 6, 2010, the largest single-day tornado-event in Arizona history occurred, producing 10 tornadoes. This included six strong (EF2+) tornadoes, an unusual event for the region. An additional tornado also touched down in Utah. Overall, the severe weather event caused 11 injuries (seven tornadic), and $4.41 billion in damage.

October 2010 Arizona tornado outbreak

A home damaged by an EF2 tornado in Bellemont, Arizona
Type	Tornado outbreak
Duration	October 6, 2010
Tornadoes confirmed	11 confirmed
Max. rating^1	EF3 tornado
Duration of tornado outbreak^2	1:58 a.m. – 1:05 p.m. MST (11 hours, 57 minutes)
Highest gust	86 miles per hour (138 km/h)
Largest hail	3.0 inches (7.6 cm)
Damage	$2.81 billion from hail, $1.6 million from tornadic events
Casualties	11 injuries (7 tornadic)[1]
^1Most severe tornado damage; see Enhanced Fujita scale ^2Time from first tornado to last tornado

Meteorological synopsis

On October 5 and 6, 2010, a strong area of low pressure situated off the coast of California produced a southerly flow of warm, moist air into Arizona. Warm surface temperatures and clear skies throughout the day on October 5 allowed for significant instability, resulting in scattered severe thunderstorms during the late afternoon, evening and overnight hours. These storms produced widespread damaging hail, ranging up to 3.0 in (7.6 cm) in diameter, and hurricane-force wind gusts of 86 mph (138 km/h). Throughout the Phoenix metropolitan area, 2 in (5.1 cm) hail caused considerable damage to hundreds of thousands of structures. A tornado watch was issued by the Storm Prediction Center earlier that day. Tornado Warnings were issued during the evening and overnight/early morning hours by the local NWS offices in Phoenix and Flagstaff when strong rotation was visible within the t-storms on radar. In the days that followed, nine tornadoes were confirmed by the National Weather Service.

Confirmed tornadoes

Confirmed tornadoes by Enhanced Fujita rating

EFU	EF0	EF1	EF2	EF3	EF4	EF5	Total
0	4	2	4	2	0	0	12

October 6 event

List of reported tornadoes - Wednesday, October 6, 2010
EF#	Location	County	State	Coord.	Time (UTC)	Path length	Max width	Comments/Damage
EF2	NW of Washington Park to NE of Lost Eden	Coconino	AZ	34.44°N 111.3°W	08:50-09:12	14.8 miles (23.8 km)	400 yards (370 m)	Hundreds of ponderosa pine trees were snapped or blown down along the path. An alligator juniper tree that was 2.5 feet (0.76 m) in diameter was snapped. Trees were blown down across Highway 87 for 2 miles (3.2 km).[2]
EF2	NW of Sedona	Coconino	AZ	34.996°N 111.878°W	11:55-12:02	4.9 miles (7.9 km)	400 yards (370 m)	Many trees were snapped or blown down. Two forest roads were completely blocked by fallen trees.[3]
EF2	W of Kachina Village to Bellemont to NNW of Fort Valley (1st tornado)	Coconino	AZ	35.106°N 111.839°W	12:07-12:44	26 miles (42 km)	500 yards (460 m)	Over 100 houses and several businesses were damaged, including at least 21 houses that were significantly damaged or destroyed. Massive tree damage was also reported with thousands of trees snapped, and campers isolated as a result. An RV dealership was impacted, with over 30 RVs demolished and thrown onto Interstate 40. 75 power poles were knocked down. The tornado passed only ^2⁄3 mile (1.1 km) east of the National Weather Service office in Bellemont. Seven people were injured. An anemometer placed by the Northern Arizona University School of Forestry measured an instantaneous wind gust of 185 miles per hour (298 km/h), a 1-second wind gust of 161 miles per hour (259 km/h), and a 3-second wind speed of 115 miles per hour (185 km/h).[4][5]
EF3	WSW of Kachina Village to Bellemont to NNW of Fort Valley (2nd tornado)	Coconino	AZ	35.05°N 111.865°W	12:54-13:50	30.06 miles (48.38 km)	800 yards (730 m)	Long track, large wedge tornado essentially paralleled the track of the previous EF2 tornado 1 mile (1.6 km) to the west. The tornado was sighted by NWS employees as this tornado passed only ^1⁄3 mile (0.54 km) west of the National Weather Service office in Bellemont. 28 rail cars were derailed. Multiple semi trucks and trailers were flipped on Interstate 40. Forest damage was severe and many roads were blocked, and thousands of trees were downed in a circular pattern in a large swath. Power poles were also snapped. Some structures were damaged. This tornado was originally rated EF-2, but was later upgraded to EF-3 in Summer 2020 after re-analysis.[6][5]
EF2	SW of Kachina Village to Western Bellemont	Coconino	AZ	34.982°N 111.927°W	13:50-14:14	18.6 miles (29.9 km)	600 yards (550 m)	Extensive forest damage occurred, with more forest roads being blocked due to fallen trees. This tornado passed 2 miles (3.2 km) west of the National Weather Service office in Bellemont as it was dissipating. The path of this tornado may have been made up of three different tornadoes instead of one longer-tracked tornado due to some evidence of extensive cycling.[7]
EF1	SSE of Chalender	Coconino	AZ	35.108°N 111.965°W	15:29-15:33	0.7 miles (1.1 km)	100 yards (91 m)	This tornado was uncovered in re-analysis done in Summer 2020 via aerial photography and surveys. Trees were snapped or uprooted.[8][5]
EF1	NNW of Sedona	Coconino	AZ	34.981°N 111.876°W	16:10-16:15	1.1 miles (1.8 km)	100 yards (91 m)	Trees were snapped or uprooted. This tornado was originally rated EF-2, but was downgraded to an EF-1 in Summer 2020 after re-analysis.[9][5]
EF0	ENE of Bumble Bee	Yavapai	AZ	34.236°N 111.973°W	17:30-17:35	4 miles (6.4 km)	50 yards (46 m)	Tornado was observed as it remained over grasslands east of Interstate 17. This was the only Arizona tornado to not move through Coconino County that day.[10][5]
EF3	SE of Tuba City	Coconino	AZ	35.909°N 111.005°W	18:15-18:20	4 miles (6.4 km)	1,100 yards (1,000 m)	Very large tornado, estimated at 0.625 mi (1.006 km) wide, tracked over an unpopulated region. Three metal truss transmission towers were destroyed - one of which was flattened - on the Navajo Nation. This damage may be indictitive of winds of 165 miles per hour (266 km/h) per the National Weather Service in Bellemont/Flagstaff. This was one of four F3/EF3 tornadoes in the state since 1950.[5][11]
EF0	Munds Park	Coconino	AZ	34.908°N 111.655°W	19:10-19:20	3.8 miles (6.1 km)	200 yards (180 m)	Tornado visually observed as it crossed Interstate 17. Minimal damage occurred.[5][12]
EF0	ESE of Flagstaff	Coconino	AZ	35.159°N 111.548°W	19:20-19:25	1.7 miles (2.7 km)	100 yards (91 m)	Tornado uncovered after initially being part of the path of the previous EF0 tornado. Little damage occurred.[5][13]
EF0	WSW of Canyonlands National Park	Wayne	UT	38.28°N 110.28°W	20:00	1.24 miles (2.00 km)	10 yards	About 30 juniper trees were snapped or uprooted in a remote forested area.
Sources: SPC Storm Reports for 10/06/10, NWS Flagstaff, NCDC Storm Data, Tornado History Project

Hailstorms

Prior to the tornado outbreak, widespread hail impacted the Phoenix metropolitan area. Three supercells caused considerable hail damage to over 150,000 homes[14] in Phoenix, Glendale, Peoria, Mesa and Scottsdale. In some instances, record or near-record-sized hailstones were measured and the largest stone reached 3.0 in (7.6 cm) in diameter.[15] Overall, the hail caused $2.81 billion (2010 USD) in damage and injured one person.[16]

See also

• Tornadoes of 2010

References

1. http://www.tornadohistoryproject.com/tornado/2010/10/6/table
2. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
3. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
4. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
5. https://www.tornadotalk.com/arizona-tornado-outbreak-october-6-2010/
6. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
7. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
8. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
9. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
10. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
11. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
12. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
13. Storm Events Database October 6, 2010 (Report). National Centers for Environmental Information. National Centers for Environmental Information. Retrieved February 4, 2021.
14. "After 2010 Phoenix-area hailstorm, damage and disputes". Arizona Republic. Retrieved 2017-02-09.
15. "Tornado Outbreak Strikes Northern Arizona". National Weather Service in Flagstaff, Arizona. National Oceanic and Atmospheric Administration. October 12, 2010. Archived from the original on October 12, 2010. Retrieved June 22, 2011.
16. "NCDC Storm Events Database". National Climatic Data Center. 2010. Retrieved February 9, 2017.

External links

• Video of the hailstorm in Phoenix