Flood watches are in effect for nearly seven million people across the Southwest, where rounds of heavy rain could trigger fast-moving flash floods with little to no warning.

Alerts covered parts of Arizona, Utah and Colorado on Monday, with many expected to remain in place into the evening. Areas under threat included Phoenix, the Grand Canyon, Zion National Park, Moab, Aspen, Vail and Durango.

The warnings follow deadly flooding at the Grand Canyon on Saturday afternoon, where one hiker was found dead and at least 14 others were reported missing after floodwaters swept through the area.

Forecasters said the risk has been heightened by deep monsoonal moisture, repeated thunderstorms and soil already soaked from previous rainfall.

In southern Arizona, some communities could see one to three inches of rain, while the most intense storms may drop more than an inch in a single hour, according to the National Weather Service.

Forecasters warned that runoff could transform dry washes and narrow slot canyons into ‘raging killer currents’ while overwhelming roads and low-water crossings.

Rivers, creeks, urban drainage systems and recent wildfire scars also face an increased risk of flooding.

Residents and tourists were told to monitor alerts and reconsider plans to hike, boat or paddleboard in slot canyons and normally dry washes.

The flooding threat is being caused by deep monsoonal moisture fueling repeated, slow-moving thunderstorms. 

Some storms could dump more than one inch of rain per hour, with isolated totals of one to three inches.

Soil already saturated by earlier storms cannot absorb much more water, causing rapid runoff into rivers, creeks, dry washes and slot canyons. 

Steep terrain, low-water crossings, poor urban drainage and wildfire burn scars further increase the risk of sudden flash flooding.

Meteorologist Max Velocity said on X: ‘Dual upper-level disturbances lifting out of Mexico and California are fueling strong atmospheric lift across the Desert Southwest. Anomalous tropical moisture pooling across the region will fuel widespread thunderstorm development. 

‘With wind shear organizing storms to repeatedly track over the exact same areas, rainfall rates could easily surpass one inch per hour. Sensitive features like slot canyons, dry washes, and recent-burn scars face life-threatening flash flood danger!’

In southern Arizona, a flood watch covered the Tohono O’odham Nation, including Sells, through Monday evening. 

Storms could dump one to three inches of rain, while rainfall from Sunday has left dry washes, creeks and road dips vulnerable to rapid flooding.

Northern and central Arizona were also under alerts, including the Grand Canyon, Flagstaff, Sedona, Prescott, Payson, the Mogollon Rim and White Mountains. Saturated ground increased the danger in slot canyons, swimming holes and wildfire burn scars.

The National Park Service announced that the body of a 46-year-old man had been recovered near Crystal Rapids along the Colorado River.

The victim’s identity has not yet been released, while the Coconino County Medical Examiner’s Office investigates.

The other missing hikers are believed to have been trekking on routes near the Bright Angel Canyon and the Phantom Ranch area of the national park.

Authorities are asking the public to help identify people who were traveling near the North Kaibab Trail from the North Kaibab Trailhead to Phantom Ranch.

This includes anyone who was staying at Bright Angel Campground, or traveling or staying in the area known as ‘the Box’ north of Phantom Ranch.

A separate watch covered Phoenix and surrounding communities, including Scottsdale, Mesa, Chandler, Glendale, Apache Junction, Casa Grande and Globe. 

Storms repeatedly passing over the same areas could produce another one to two inches of rain and rapid runoff.

Alerts also extended across western and southwestern Arizona, including Buckeye, Avondale, Tonopah, Gila Bend, Central La Paz County and the Sonoran Desert National Monument. 

The Northwest Plateau, including the western Grand Canyon, Tuweep and Colorado City, faced heavy rain capable of forcing streams over their banks and flooding roads.

In Utah, watches stretched from the central mountains to Zion, Bryce Canyon and Capitol Reef national parks. 

Glen Canyon, Lake Powell, the Sanpete and Sevier valleys and Castle Country were also included. Saturated soil left those areas especially vulnerable, while flooding could strike dry washes, slot canyons and several recent burn scars.

Southeastern Utah alerts covered Moab, Arches, Canyonlands, Blanding, Bluff and Monticello.

The same storm system threatened much of western Colorado, including Grand Junction, Aspen, Vail, Montrose, Gunnison, Telluride, Ouray and Cortez. 

Several rounds of heavy rain could trigger flooding around rivers, creeks and recent wildfire scars.

A separate watch covered the Animas and San Juan river basins in southwestern Colorado from Monday morning through the evening, including Durango, Bayfield, Ignacio and Pagosa Springs.

The NWS urged residents and tourists to monitor flash-flood warnings and be prepared to act immediately.

A South Carolina woman accused of stabbing a Lyft driver 11 times and then stealing his vehicle will remain behind bars after a judge denied her bond Friday, despite her attorney’s argument that she was in the midst of a serious mental health crisis at the time of the alleged attack.

Naziyha Weatherall is charged in Greenville County with attempted murder, carjacking and possession of a weapon during a violent crime. Court records show the case is tied to an alleged incident on April 22.

During Friday’s bond hearing, prosecutors described the accusations as a “frightening factual scenario,” according to FOX Carolina, and urged the court to consider Weatherall an extreme threat to public safety.

“The victim was simply just trying to do his job and was stabbed 11 times,” a solicitor said, according to FOX Carolina. “Not only was he stabbed 11 times, his car was then carjacked by this defendant.”

The driver’s wife appeared in court on his behalf, saying the trauma of the alleged attack prevented him from attending.

“What concerns us most is that happened while my husband was simply working,” she said. “He was not looking for any confrontation, he was providing a service to a person. If this level of violence could happen to someone who was simply doing his job, we are concerned about potential risks to other people in our community.”

Weatherall’s lawyer urged the court to view the allegations through the lens of her mental state, saying she had never previously been charged with a crime and was in the throes of a psychiatric emergency.

The defense said paranoia had convinced Weatherall that others were monitoring her and trying to harm her, prompting her to summon a ride to report her fears to police.

“Her mother even called the police station to let them know she was on the way to make a report,” the attorney said. “During that, the crisis got worse.”

The attorney said Weatherall believed she was being trafficked, panicked during the ride and had been diagnosed with schizophrenia and other mental health conditions.

The defense said Weatherall is now medicated, stable and competent, and asked the court to release her so relatives and a social worker could arrange placement at a treatment facility.

Weatherall’s mother apologized to the driver’s family while asking the court to consider her daughter’s mental state.

“She’s not a criminal. She would never, ever, ever hurt anybody like that,” her mother said. “And I understand the family’s side, I truly do, because we are all suffering. We all are.”

A judge ordered competency and observation evaluations in June, court records show. On Friday, the judge denied Weatherall’s bond request and ordered that she remain jailed pending a psychological evaluation scheduled for September.

Lyft told News Media it permanently removed the rider accounts involved from its platform and has continued assisting law enforcement.

“Violence like this has no place in the Lyft community or in our society,” a Lyft spokesperson said. “The driver’s well-being has been our priority, and we have reached out to them and their family to offer support.”

News Media has reached out to Weatherall’s attorney for comment.

A Texas father of three captured what appeared to be a joyful vacation moment at the Grand Canyon, smiling for a selfie amid the park’s sweeping rock walls, just one day before he disappeared with his hiking group during deadly flash flooding that has killed at least one person and left roughly 15 others unaccounted for.

Dr. John Giusti, 46, a chiropractor from Granbury, Texas, had been hiking and camping with two friends when intense rainfall triggered a sudden surge of water, mud and debris through Bright Angel Canyon on Saturday.

One of the last images Giusti shared from the trip shows him standing before the Grand Canyon’s dramatic cliffs — a poignant snapshot of the outdoorsman before he vanished in the fast-moving floodwaters.

Giusti’s younger sister, Valerie Gibbs, told The New York Times that it was his first visit to the Grand Canyon.

Family members described him as healthy, energetic and passionate about hiking and running. They said they last heard from him around 2 p.m. Saturday, shortly before the destructive flash floods swept through the area.

His wife, Janet Giusti, issued a desperate plea for prayers after learning that her husband’s hiking group was among those unaccounted for.

“We ask our ChiroHabit community to please lift up my husband, his hiking group, and our families in your thoughts and prayers during this time,” she wrote in a Facebook post that was later deleted, according to the Times. 

“Please pray for Dr. John’s safety,” she separately wrote in an update shared by his practice. 

Giusti is one of roughly 15 people the National Park Service was still trying to account for Sunday following the flash flood in Bright Angel Canyon and the Phantom Ranch area.

Separately, a 46-year-old man was confirmed dead.

His body was recovered Sunday near Crystal Rapids along the Colorado River, the National Park Service said. Officials have not released his identity.

The disaster unfolded around 2:30 p.m. Saturday, when intense rainfall sent torrents racing through the canyon. More than 60 people were ultimately airlifted from Phantom Ranch and the lower North Kaibab Trail.

The flooding obliterated footbridges over Bright Angel Creek, ripped debris and metal structures into the Colorado River and severely damaged infrastructure throughout the canyon. The park’s water pipeline was also knocked out, forcing emergency water restrictions and the closure of overnight accommodations. 

The NPS is asking anyone who may have information about hikers or backpackers in the Bright Angel Creek corridor Saturday to contact its Investigative Services Branch.

The request includes people who may have traveled the North Kaibab Trail, stayed at Bright Angel Campground or been in an area known as “the Box” north of Phantom Ranch. 

Arizona Gov. Katie Hobbs also offered her support to the families waiting for answers.

“My heart is with the families and loved ones of every person unaccounted for after the flash flooding at the Grand Canyon. DEMA is coordinating with NPS and Coconino County Emergency Management to support search and recovery efforts.

“Thank you to the first responders on the ground working to keep our communities safe when disaster strikes,” she wrote Sunday. 

The park remained closed in several affected areas as crews continued the search and assessed the extensive damage.

Two friends who headed out on a late-night canoe trip to witness the Bay Area’s striking bioluminescent waters were later found dead, officials said.

Casey Flynn Melia, 36, and a second person whose name has not been released were discovered Sunday at about 1:30 p.m. after setting off around midnight on Tomales Bay, a narrow coastal inlet in Marin County, California.

The unidentified man was found in the water, while Melia was located on shore just north of Hog Island, NBC Bay Area reported.

Both men were pronounced dead at the scene.

Authorities said Melia, who lived in San Francisco, and his friend had been wearing life jackets during the outing.

They were reported missing after they failed to return from their trip as planned, the Marin County Fire Department told the San Francisco Chronicle. 

The details of what led to their deaths remain unknown. The investigation is being led by the Sonoma and Marin County Sheriff’s Offices. 

Melia’s official cause of death is pending. Routine toxicology testing and a post-mortem examination are scheduled for later this week, the Marin County Sheriff’s Office said. 

Tomales Bay is known for its dangerously cold water, hazardous conditions near the sandbar and the mouth, and strong afternoon winds. 

The friends had planned to camp at White Gulch Beach, which is located directly on the western shore of Tomales Bay, according to the Chronicle. 

They ventured into the water to witness the annual bioluminescence, a phenomenon that is sometimes visible along the bays and coast in California. 

The spectacle takes place when the small organisms in algae, known as dinoflagellates, bloom after they become agitated. 

The tiny organisms emit flashes of light through a chemical reaction with a molecule called luciferin and an enzyme known as luciferase, causing a vibrant blue color to glow in the water. 

Bioluminescence takes place every year from June to October in Tomales Bay. 

The phenomenon also takes place in other locations across the US, including the Outer Banks, North Carolina. 

It also occurs in Vieques, Puerto Rico; Space Coast, Florida; San Diego, California; San Juan Island, Washington; Gulf Shores, Alabama; Tybee Island, Georgia; and Kona, Hawaii, according to Travel + Leisure. 

Bioluminescence occurs most commonly among squid, fish, and ‘gelatinous zooplankton’, the National Oceanic and Atmospheric Administration (NOAA) said. 

The ‘gelatinous’ species include jellyfish, comb jellies, siphonophores, and other sea animals that are mostly made of water, the agency added. 

The Daily Mail contacted the Sonoma and Marin County Sheriff’s Offices, as well as the Marin County Fire Department and the Marin County Coroner’s Office for comment.