September 2023 southwestern U.S. floods

September 2023 southwestern U.S. floods

A mesoscale precipitation discussion issued by the Weather Prediction Center concerning flash flooding across the southwestern United States on September 1, 2023
Cause	Heavy rains
Meteorological history
Duration	September 1 — September 3, 2023
Flood
Maximum rainfall	>4 inches (100 mm) east of Palo Verde, California
Overall effects
Fatalities	1
Damage	$550 million (2023 USD)[1]
Areas affected	Southeastern California, southern Nevada, northwestern Arizona, southwestern Utah

In a period of three days on September 1–3, 2023, flooding occurred as part of a seasonal monsoon season across portions of the Southwestern United States, including California, Nevada, Arizona, Utah and the Las Vegas Valley. Muddy terrain during the Burning Man festival stranded more than 70,000 people.[2]

Meteorological synopsis

Across the Desert Southwest, training showers and thunderstorms developed as they headed northward by an almost-undirectional flow, which was situated between a low-pressure area across California, and a retreating ridge of high pressure to the east of the low.[3] Southerly flow between the low and the high pressure ridge caused moisture to be driven northward, surface-based convective available potential energy values of 1000–2000 j/kg yielded conditions for heavy rainfall-producing convective systems, and weak shortwaves combined with shear between 25–35 knots (29–40 mph; 46–65 km/h; 13–18 m/s) also provided thunderstorm development.[3] On September 1, the Weather Prediction Center also stated in a mesoscale precipitation discussion that repeated rounds of thunderstorms were possible across the southwestern United States.[4]

Impact

Nevada

Interstate 15 near the California—Nevada border and south of Jean was shut down due to flooding.[5][6][7] At least 24 water rescues occurred and more than 30 vehicles submerged in floodwaters as crews from Las Vegas Fire & Rescue assisted with search and rescue efforts.[7][8][9] One death, possibly due to drowning from floodwaters, occurred near Las Vegas in West Valley, Nevada.[10] A downpour also temporarily delayed a UNLV—Bryant college football game at Allegiant Stadium.[11] Portions of the Las Vegas Strip flooded, including a channel outside of The Linq as the city of Las Vegas was under a flash flood warning.[12] The Nevada Department of Transportation closed travel lanes on Nevada State Route 447.[13] Debris closed all but one lane on U.S. Route 93 northbound.[14] The National Weather Service office in Las Vegas recorded 0.88 inches (22 mm) of rainfall, which was the wettest day in September in 11 years.[15]

More than 4,000 power outages occurred, and 108 flights were cancelled, along with 673 delayed flights at Harry Reid International Airport.[16] A ground stop was also briefly issued for the airport.[14]

Burning Man

Main article: Burning Man 2023

Rainfall and a rainbow at Burning Man

Torrential rainfall flooded the Burning Man festival, which was closed throughout the remainder of the scheduled event afterwards as thunderstorms also flooded the Black Rock Desert.[17] Diplo and Chris Rock, who attended the festival, fled 5–6 miles (8.0–9.7 km) from the festival site through mud caused by the floods.[18][19][20] Mud across roads near the festival closed vehicle traffic stranding at least 73,000 people after the festival ended.[17][21] According to Pershing County sheriff Jerry Allen, some vehicles have caused damage to the playa. Allen urged attendees to avoid driving out of the festival.[22] The burning of the Man was delayed[23] and one person died.[24] Former acting solicitor general Neal Katyal took a six-mile (10 km) hike, describing the journey as "harrowing".[25]

California

More than 12 water rescues occurred in Imperial County, as several roads in that county were also closed due to debris and flooding.[26] Portions of California State Route 78 in Imperial Valley were closed, and the California Highway Patrol, United States Coast Guard's San Diego sector, and the Imperial County Fire Department assisted with flood rescue operations.[26] More than 4 inches (100 mm) fell across portions of Imperial County and east of Palo Verde.[26] Road closures also occurred in Coachella Valley, and the Riverside County Emergency Management Department coordinated with numerous emergency management departments to address damage and concerns.[27] Several businesses and homes, along with agricultural fields, were flooded in Niland, as more than 4 inches (100 mm) of rain fell east of the area.[28]

Arizona

Several streets were flooded in a Yuma neighborhood as the city received up to 4 inches (100 mm) in two hours.[29] Yuma, Mohave, Pima, and La Paz counties were under a flash flood warning, and a funnel cloud was reported near San Luis.[29] Cities in western Arizona, including Kingman, Bullhead City, and Fort Mohave were also under flash flood warnings.[30] High wind gusts caused blowing dust across portions of the state, which led to a delay in an Arizona State Sun Devils football game.[31] There were also wind gusts of up to 71 miles per hour (114 km/h) at Phoenix Sky Harbor International Airport, where several flights there were diverted,[32] and more than 27,000 power outages occurred in Maricopa County.[31] A rainfall record was set in Yuma on September 2, breaking the previous record of 1.67 inches (42 mm).[28]

Elsewhere

Mudslides forced closures on portions of U.S. Route 6 and U.S. Route 191 in Carbon County.[33] Severe thunderstorm warnings were issued for portions of western Utah.[34] Heavy rainfall caused mud and rockslides at Bryce Canyon National Park, and forced the closure of Navajo Loop Trail.[15] Severe thunderstorm warnings and flood advisories were also issued for Eastern Idaho.[35]

References

1. "Q3 Global Catastrophe Recap October 2023" (PDF). Aon Benfield. Retrieved October 31, 2023.
2. Blanco, Andrea (September 2, 2023). "Burning Man turns to mud pit in heavy downpours after being delayed by hurricane". The Independent. Archived from the original on September 2, 2023. Retrieved September 2, 2023.
3. Weiss, Joshua (September 1, 2023). "Mesoscale Precipitation Discussion 1020". Weather Prediction Center. Archived from the original on 2023-09-04. Retrieved 2023-09-04.
4. Otto, Richard (September 1, 2023). "Mesoscale Precipitation Discussion 1015". Weather Prediction Center. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
5. Ray De La Cruz, Rene (September 4, 2023). "Traffic resumes after flooding shuts down Interstate 15 near California-Nevada border". Victorville Daily Press. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
6. Kaufman, Carrie (September 2, 2023). "I-15 Southbound just north of Primm". X (formerly Twitter). Archived from the original on October 15, 2023. Retrieved September 4, 2023.
7. "Las Vegas drying out after 2 days of heavy rainfall that prompted water rescues, possible drowning". AP News. September 3, 2023. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
8. "Last night, we responded to 24 swift water rescue events including: · 30-35 vehicles stranded in water · 10 – 12 people rescued from standing or moving water". X (formerly Twitter). September 2, 2023. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
9. "We had a busy morning with two swift water rescues, both around 7 a.m.: - Three vehicles stranded in the water near Sahara and Decatur - Three vehicles stalled in water near Charleston and Commerce". X (formerly Twitter). September 1, 2023. Archived from the original on September 3, 2023. Retrieved September 4, 2023.
10. Staff, News 3 (September 2, 2023). "Las Vegas Fire and Rescue locate believed drowning victim in west valley". KSNV. Archived from the original on September 3, 2023. Retrieved September 4, 2023.
11. Review-Journal, Adam Hill Las Vegas (2023-09-02). "UNLV game delayed by rain at Allegiant Stadium, Raiders' home | Las Vegas Review-Journal". Archived from the original on 2023-09-04. Retrieved 2023-09-04.
12. Tumin, Remy (September 1, 2023). "Parts of Las Vegas Strip Flood After Heavy Rain". The New York Times. ISSN 0362-4331. Archived from the original on September 3, 2023. Retrieved September 4, 2023.
13. Thomas, Carly (September 2, 2023). "Diplo and Chris Rock Escape Burning Man Festival After Catching Ride in Fan's Pickup Truck". The Hollywood Reporter. Archived from the original on September 3, 2023. Retrieved September 3, 2023.
14. "Heavy rain causes flooded streets, water rescues in Southern Nevada". KSNV. September 1, 2023. Retrieved October 29, 2023.
15. Sistek, Scott (September 2, 2023). "Monsoon storms continue pounding Southwest, charge north after days of heavy flooding in Las Vegas". FOX Weather. Retrieved December 1, 2023.
16. Roberts, Alyssa (September 2, 2023). "Thousands lose power, hundreds of flights delayed as rain drenches Las Vegas Valley". KTNV 13 Las Vegas. Archived from the original on September 5, 2023. Retrieved September 5, 2023.
17. Mae Czachor, Emily (September 3, 2023). "Investigation launched into death at Burning Man, with thousands still stranded in Nevada desert after flooding". CBS News. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
18. Deliso, Meredith; Hutchinson, Bill (September 3, 2023). "Death reported at Burning Man as attendees asked to conserve food after flooding strands thousands". ABC News. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
19. "just walked 5 miles in the mud out of burning man with chris rock and a fan picked us up". X (formerly Twitter). September 2, 2023. Archived from the original on September 3, 2023. Retrieved September 4, 2023.
20. Barsanti, Sam (September 3, 2023). "Diplo and Chris Rock made a harrowing escape from Burning Man". The A.V. Club. Archived from the original on September 3, 2023. Retrieved September 3, 2023.
21. Hughes, Trevor; Bacon, John (September 3, 2023). "A sea of mud, overflowing Porta-potties and a rain delay: Burning Man updates". Reno Gazette Journal. Archived from the original on October 15, 2023. Retrieved September 4, 2023.
22. Deliso, Meredith; Hutchinson, Bill (September 3, 2023). "Death reported at Burning Man as attendees asked to conserve food after flooding strands thousands". ABC News. Archived from the original on September 3, 2023. Retrieved September 3, 2023.
23. Hughes, Trevor; Bacon, John (September 3, 2023). "Thousands still stuck in the muck at Burning Man festival; 1 death reported". USA Today. Archived from the original on September 3, 2023. Retrieved September 3, 2023.
24. Betts, Anna; Mayorquin, Orlando; Medina, Eduardo (September 3, 2023). "Authorities Investigate Death at Burning Man as Thousands Remain Trapped". The New York Times. Archived from the original on September 3, 2023. Retrieved September 3, 2023.
25. Alsup, Dave (September 3, 2023). "Attendee describes his "incredibly harrowing" 6-mile hike out of Burning Man". CNN. Archived from the original on September 3, 2023. Retrieved September 3, 2023.
26. Feather, Bill (September 2, 2023). "Late-summer monsoon leads to flash flooding, rescues in Imperial County". NBC 7 San Diego. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
27. News Service, City (September 3, 2023). "RivCo Agencies Respond To Eastern Coachella Valley Flooding". Banning-Beaumont, CA Patch. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
28. "2023 Monsoon Season Review". National Weather Service Phoenix, Arizona. Retrieved January 22, 2024.
29. Staff, FOX 10 (September 3, 2023). "Heavy rains cause flash flooding in western Arizona". FOX 10 Phoenix. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
30. "US: Flash flood warning in effect for parts western Arizona through 05:45 MST Sept. 1". Crisis24. September 1, 2023. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
31. Elamroussi, Aya; Shackelford, Rob (September 1, 2023). "Severe thunderstorms in Arizona knock out power to tens of thousands with high winds, heavy rains and dust storm warnings". CNN. Retrieved November 30, 2023.
32. Gabriel, Angeli (September 1, 2023). "Las Vegas roads swamped as monsoon thunderstorms trigger flash flooding". FOX Weather. Retrieved December 1, 2023.
33. Houck, Michael (September 3, 2023). "Major mudslide closes U.S. Highway 6 in Carbon County". KSL-TV. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
34. Weather Team, 2News (September 3, 2023). "Storm moving deeper into Utah after hitting areas with wind, rain, hail". KUTV. Archived from the original on September 4, 2023. Retrieved September 4, 2023.
35. Severe thunderstorm warning, flood advisory issued for several counties, East Idaho News, September 3, 2023