Beginning on July 24, 2022, and lasting for a week, many flash flooding events hit several areas of the United States. These areas included parts of Missouri and Illinois, especially Greater St. Louis, Eastern Kentucky, Southwest Virginia, parts of West Virginia, and the Las Vegas Valley. Several rounds of severe thunderstorms began in Missouri on July 24, culminating during July 25 and 26, when St. Louis broke its previous 1915 record for the most rainfall in a span of 24 hours. Governor Mike Parson declared a state of emergency on July 26. Over one hundred people were rescued from floods, and two people were killed. Late on July 27 and into July 28, historic flooding began in central Appalachia, particularly in Kentucky, where a state of emergency was declared. A total of 38 people were killed in Kentucky as a direct result of flooding, with a 39th fatality occurring days later during cleanup efforts and a 40th coming in September during cleanup efforts in Pike County.
Late July 28, another unprecedented flash flooding event occurred in Las Vegas after parts of the city saw over an inch of rainfall. Much of the Las Vegas Strip became inundated, with roads, casinos, and parking garages being affected and flights being delayed or cancelled. More flooding continued from July 30 to August 1 in Arizona, including Phoenix and Flagstaff, California, including Death Valley National Park, and again in the same areas of Eastern Kentucky. In all, 41 people were killed during the flooding events: 39 in Kentucky on July 28 and 2 in Missouri on July 26.
More flooding events continued throughout August, impacting areas such as Death Valley, the Dallas–Fort Worth metroplex, and central Mississippi. A flash flood in Zion National Park in Utah led to one fatality. The Dallas flooding on August 22 led to an additional fatality and four injuries.
Meteorological synopsis
On the morning of July 26, the Weather Prediction Center (WPC) issued a moderate risk outlook for excessive rainfall over portions of eastern Missouri and southern Illinois and Indiana associated with an expected band of training thunderstorms over the region. Later, the National Weather Service issued its first-ever flash flood emergencies for Saint Louis. By the end of July 26, St. Peters, Missouri recorded a total of of rainfall, while other areas of St. Charles County received over . Other parts of Greater St. Louis totaled as much as of rain. Additionally, more than of rain fell in the town of Mexico in central Missouri, with similar rainfall totals being reported in southern Illinois. Parts of Kentucky and West Virginia were affected by flooding on July 26 as well, including Johnson, Magoffin, and Floyd counties in Kentucky and Mingo and McDowell counties in West Virginia.
Training thunderstorms began to form over Eastern Kentucky during the early hours of July 27, producing heavy rainfall periodically throughout the day. Jackson, Kentucky had its second-wettest day on record (since 1981), with of rain falling. During the late evening and overnight hours, a more substantial band of heavy rain and thunderstorms moved west to east along a stalled frontal boundary, resulting in subsequent extreme flooding across the counties of Perry, Knott, Breathitt, Letcher, Leslie, Clay, Owsley, Wolfe, Harlan, Johnson, Magoffin, Floyd, and Pike. Flooding was also reported in Southwest Virginia, in the areas of Wise and Dickenson counties, and the independent city of Norton, which are along the Kentucky border. On the morning of July 28, the WPC issued a moderate risk outlook for excessive rainfall over portions of Central and Eastern Kentucky and West Virginia. The rainfall began to move towards West Virginia and central Kentucky the following day, and began to encompass almost all of West Virginia on July 29. On the morning of July 29, the WPC issued a moderate risk outlook for excessive rainfall, but shifted it into Eastern Kentucky and almost all of West Virginia.
On the morning of July 31, a third moderate risk outlook for excessive rainfall was issued by the WPC over portions of Eastern Kentucky, with more flooding occurring that night over the same areas as four days earlier.
Elsewhere on July 30 and 31, Phoenix and Flagstaff, Arizona, along with rural areas of Arizona and southeast California sustained flooding due to heavy rain associated with the Southwest monsoon. Near Kingman, over of rain fell in approximately 15 minutes on July 31, associated with widespread thunderstorm activity over both states and southern Nevada.
More rainfall impacted the same areas of Eastern Kentucky on July 31 and August 1, leading to renewed flooding in those areas, while areas of eastern Illinois, such as Jasper and Richland counties, picked up as much as of rain from August 1 into August 2. On the morning of August 2, the Weather Prediction Center issued a moderate risk of excessive rainfall for parts of southern Illinois and Indiana and parts of western Kentucky.
Also on August 2, central Mississippi, including parts of Madison, Yazoo, Holmes, and Attala counties, received as much as of rainfall, causing flooding that impacted roads and homes.
On the morning of August 7, WPC issued a moderate risk for excessive rainfall across portions of northeastern Iowa and southern Wisconsin.
Impacts
California July 30–31
In southern California, Death Valley National Park and the Mojave National Preserve were impacted by flooding on July 30 and 31, resulting in numerous road and campground closures and damaged/destroyed vehicles. Heavy rain in the San Bernardino National Forest resulted in mudslides that blocked roads near Yucaipa.
August 5 All roads into Death Valley National Park were closed due to major flash flooding. Rainfall in Death Valley totaled , setting a new (since surpassed) single-day rainfall record; the amount was around 75 percent of the area's annual average precipitation.Record Floods Strand 1K People in Death Valley National Park , US News, August 5, 2022 After the storm, the Federal Highway Administration gave $11.7 million to the National Park Service to fix roads in the park following the flooding.$12M Provided to Repair Flood Damaged Roads in Death Valley National Park , NBC Los Angeles, August 16, 2022
Las Vegas Valley July 28 On the night of July 28, another flash flooding event occurred in the Las Vegas Valley in southern Nevada. Harry Reid International Airport saw of rainfall in two hours, the monthly average for all of July. A ground stop was issued at the airport.FAA issues 'ground stop' at Harry Reid Airport during storms , 8NewsNow, July 29, 2022 Parts of Clark County saw of rain, causing disruptive flash flooding. This heavy rain flooded casinos and parking garages along the Las Vegas Strip.
Just one mile away from the airport, the UNLV campus received substantially more rainfall, totaling over . Casinos on the Strip that were impacted included Caesars Palace and Planet Hollywood, with water pouring through parts of the ceilings into the buildings. Las Vegas Boulevard and Main Street, especially in downtown and the area of the Strip, were covered in water, creating traffic problems. Fire departments and first responders had 330 calls for flooding and swift water service, with seven people being rescued from floodwaters.
The seasonal monsoon rains in the area partially contributed to a water rise of in Lake Mead from July 26 to 31, along with water releases from Lake Powell.
Arizona July 25–30 Rain beginning on July 25 in the Flagstaff, Arizona area associated with the monsoon season led to increased flash flooding concerns throughout the week, due in part to the burn scars from the recent wildfires. By July 27, Flagstaff mayor Paul Deasy had declared a state of emergency as numerous areas around Flagstaff had been impacted by flooding, including Mt. Elden Estates, Paradise, Grandview, and Sunnyside. Other neighborhoods such as Cheshire, Coconino Estates, Creighton Estates, Coyote Springs, Anasazi Ridge were later added to the state of emergency order. Schultz Creek overflowed in the area, resulting in the temporary closure of US 180 on the west side of Flagstaff.
On July 30, areas on the north side of Phoenix along I-17 received of rain, mostly within one hour. This led to flooding of roads and low-lying areas and prompted four water rescues, two of which were from partially submerged vehicles. A voting precinct in Downtown Phoenix was closed by the Maricopa County Elections Department due to flooding in the building, forcing it to be relocated elsewhere within the building for subsequent days. Numerous streets in Phoenix became temporarily flooded due to the heavy rain. Several homes and apartment complexes became flooded as well.
Utah August 19 One woman was killed when she was swept away in a flash flood in Zion National Park. Her body was discovered on August 22 after a search involving over 170 people.
Texas
August 21–22 Starting late on August 21, 2022, and going into the next morning, a significant flash flooding event occurred in the Dallas–Fort Worth metroplex in Texas, killing one person and injuring four others. Some parts of the metroplex saw over of rain, which is the usual rainfall total for the area during all of summer. Before this rainfall event, 2022 was shaping up to be one of the hottest and driest years ever recorded in Texas.On the Bright Side, Dallas' Flash Floods Put a 'Dent' Into The Drought , Dallas Observer, August 23, 2022 On the morning of August 21, the Weather Prediction Center (WPC) issued a moderate risk for excessive rainfall for North and Northeast Texas. On August 22, WPC issued a new moderate risk for excessive rainfall for North and Northeast Texas as well as portions of North Louisiana. At 1:20 am. CDT on August 22, the National Weather Service issued a flash flood warning for the Dallas metroplex.
Overnight on August 21, Dallas Fort Worth International Airport reported of rainfall over a one-hour timeframe, setting the record for the most rainfall in a single hour ever for the airport. By 8 am. CDT on August 22, parts of the Dallas–Fort Worth metroplex had received over of rain. The amount of rainfall that Dallas normally sees during all of summer fell within 24 hours, breaking a record for most rain in 24 hours since 1932 and making 2022 the wettest August in Dallas history. This also meant that, despite 67 consecutive days with no measurable precipitation during the summer, Dallas still had their 9th wettest summer on record.The year in North Texas weather: A look back at the memorable meteorological events of 2022 , WFAA, December 30, 2022
The flooding event caused over 314 car crashes and 319 high water calls. Parts of the Dallas area got up to of rain. Nearly 300 flights were cancelled and 900 were delayed between the two Dallas airports. Dallas Fort Worth International Airport, and 37,000 other customers, lost power.Dallas Flood Live Updates: Water Rescues, Roads Closed, Flights Delayed , Weather Underground, August 22, 2022 One person was killed and four people were injured in the floods. Certain rivers reached moderate flood stage as they reached over .
Around 10:15 am. CDT on August 22, the storms associated with the flooding event produced an EF1 tornado that impacted Smith County, approximately east of downtown Dallas. Minimal damage occurred to a school and other structures near Winona. Due to the floods, drought improved across parts of northern Texas.
Mississippi
August 2 Areas near Canton, Mississippi also received very heavy rainfall on August 2, leading to flash flooding that trapped people in homes in Madison County. Numerous people were rescued by fire department crews from houses and offices after some areas received up to of rainfall in a few hours. Roads were closed due to high water, and vehicles were submerged along roadways and in parking lots.
August 24–27