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Tropical Storm Hilary swirled northward overnight just off the coast of Mexico's Baja California peninsula, no longer a hurricane but still carrying so much rain that forecasters said "catastrophic and life-threatening" flooding is likely across a broad region of the southwestern US.
Early this morning Hilary was located about 350 kilometres south-southeast of San Diego, the National Hurricane Centre reported. Hilary had maximum sustained winds of 110km/h and was moving northwest at 41km/h.
The Mexican cities of Ensenada and Tijuana remained directly in the tropical storm's path, and meteorologists warned that despite weakening, the storm remained treacherous.
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One person drowned on Saturday in the Mexican town of Santa Rosalia, on the peninsula's eastern coast, when a vehicle was swept away in an overflowing stream. Rescue workers managed to save four other people, said Edith Aguilar Villavicencio, the mayor of Mulege township.
It was not immediately clear whether officials considered the fatality related to the hurricane, but video posted by local officials showed torrents of water coursing through the town's streets.
Forecasters said the storm was still expected to enter the history books as the first tropical storm to hit Southern California in 84 years, bringing flash floods, mudslides, isolated tornadoes, high winds and power outages. Authorities issued an evacuation advisory for Santa Catalina Island, urging residents and beachgoers to leave the tourist destination 37 kilometres off the coast.
Elizabeth Adams, a meteorologist at the National Weather Service San Diego office, said rain could fall up to 7.62 centimetres an hour across Southern California's mountains and deserts, from late Sunday morning into the afternoon. The intense rainfall during those hours could cause widespread and life-threatening flash floods.
California Governor Gavin Newsom proclaimed a state of emergency, and officials had urged people to finish their preparations before sundown Saturday. It would be too late by Sunday, one expert said.
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The hurricane is the latest major climate disaster to wreak havoc across the US, Canada and Mexico. Hawaii's island of Maui is still reeling from last week's blaze that killed over 100 people and ravaged the historic town of Lahaina, making it the deadliest US wildfire in more than a century. In Canada, firefighters on Saturday continued to battle blazes during the nation's worst fire season on record.
Hilary already brought heavy rain and flooding to Mexico and the southwestern US on Saturday, ahead of the storm's expected Sunday border crossing. Forecasters warned it could dump up to 25 centimetres — a year's worth of rain for some areas — in southern California and southern Nevada.
"This does not lessen the threat, especially the flood threat," Jamie Rhome, the US National Hurricane Centre's deputy director, said during a Saturday briefing to announce the storm's downgraded status. "Don't let the weakening trend and the intensity lower your guard."
Meteorologists also expected the storm to churn up "life-threatening" surf and rip currents, including waves up to 12 metres high, along Mexico's Pacific coast. Dozens sought refuge at storm shelters in the twin resorts of Los Cabos at the southern tip of the Baja peninsula, and firefighters rescued a family in San Jose del Cabo after the resort was hit by driving rain and wind.
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In Tijuana, fire department head Rafael Carrillo voiced the fear at the back of everyone's mind in the border city of 1.9 million people, particularly residents who live in homes on steep hillsides.
"If you hear noises, or the ground cracking, it is important for you to check it and get out as fast as possible, because the ground can weaken and your home could collapse," Carrillo said.
Tijuana ordered all beaches closed Saturday, and set up a half dozen storm shelters at sports complexes and government offices.
Mexico's navy evacuated 850 people from islands off the Baja coast, and deployed almost 3000 troops for emergency operations. In La Paz, the picturesque capital of Baja California Sur state on the Sea of Cortez, police patrolled closed beaches to keep swimmers out of the whipped-up surf.
The US hurricane centre posted tropical storm and potential flood warnings for Southern California from the Pacific coast to interior mountains and deserts as far north as eastern Oregon and Idaho. The San Bernardino County sheriff issued evacuation warnings for several mountain and foothill communities ahead of the storm, while Orange County sent out its own alert for anyone living in a wildfire burn scar in the Santa Ana Mountains' Silverado and Williams canyons.
Authorities in Los Angeles scrambled to get the homeless off the streets and into shelters, and officials ordered all state beaches in San Diego and Orange counties closed.
Across the region, municipalities ran out of free sandbags and grocery shelves emptied out as residents stockpiled supplies. The US National Park Service closed California's Joshua Tree National Park and Mojave National Preserve to keep visitors from becoming stranded amid flooding.
Major League Baseball rescheduled three Sunday games in Southern California, moving them to Saturday as part of split doubleheaders, and SpaceX delayed the launch of a satellite-carrying rocket from a base on California's central coast until at least Monday.
The White House said President Joe Biden had been briefed on the latest preparedness plans ahead of the hurricane's turn to the US "I urge everyone, everyone in the path of this storm, to take precautions and listen to the guidance of state and local officials," he said.
The Federal Emergency Management Agency announced that it has officials inside California's emergency preparedness office and teams on standby with food, water and other help as needed.
Hilary on Friday had rapidly grown into an exceedingly dangerous Category 4 major hurricane, with its top sustained winds peaking at 230km/h. Its winds dropped to 185km/h early Saturday as a Category 3 storm, before further weakening to 161km/h as a Category 2.
By Sunday it was moving north-northwest at 33km/h. The hurricane brushed past Punta Eugenia on the Pacific coast and was expected to make landfall along a sparsely populated area of the peninsula south of the Pacific port city of Ensenada.
Meanwhile one of several budding storm systems in the Atlantic Ocean became Tropical Storm Emily on Sunday, according to the National Hurricane Center. It was located far from land, about 1615 kilometres west-northwest of the Cabo Verde Islands with maximum sustained winds of 85km/h. Emily was moving at about 17km/h in the open ocean.
