Hilary was wet and blustery in San Diego, but West Coast conditions caused her to ‘collapse’
San Diegans evaluated damage Monday from record August rains caused by historic Tropical Storm Hilary
A day after Hilary became the first tropical storm since 1930 to directly hit San Diego County, the region’s leaders began assessing the damage left in its wake and expressing gratitude that the storm didn’t pack the punishing punch that some had expected.
The storm was extremely wet, dumping record amounts of rain across the San Diego region.
But Hilary, which had grown to a Category 4 hurricane while spinning off the west coast of Mexico, caused limited damage by the time it limped into San Diego County. Hilary was severely weakened by the conditions that typically prevent such storms on the West Coast.
Despite reports of hundreds of fallen trees and some roadway flooding, the county appeared to have escaped major damage. More serious flooding and widespread damage was reported in Baja California and the desert regions northeast of the county.
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“We prayed for the best case, we prepared for the worst case,” Eric Dargan, the city of San Diego’s chief operating officer, said at a Monday morning news conference at a county facility in Kearny Mesa.
As officials applauded the preparation efforts of both county and city staff, as well as the public, forecasters continued tracking Hilary’s remnants and studying how the storm lost its bite.
“The biggest thing with Hilary is that she weakened very quickly as she progressed north,” Elizabeth Adams, a meteorologist with the National Weather Service in San Diego, said by phone Monday.
Adams said the cold waters of the Pacific Ocean, the terrain of Baja California, where Hilary first made landfall, and the wind shear, or the changing of wind speeds and direction with height, sapped Hilary of its power.
“Those factors are very conducive for a hurricane to collapse,” Adams said. “All those things were working against this system.”
Adams said Hilary also moved through San Diego County at about 20 to 25 mph, which is “really fast for a tropical system.” Hurricanes and tropical storms that hit the East Coast and Gulf areas of the U.S. typically move at speeds between 5 and 10 mph, creating the feeling that they “sit there for a really long time,” Adams said.
Comparatively, the local “crunch time” for Hilary was about 18 to 24 hours, Adams said.
The storm made initial landfall about 11 a.m. Sunday south of Ensenada, Mexico. Forecasters predicted the center of the storm would arrive in San Diego around 6 p.m., but it actually hit much sooner, moving through between roughly 2:30 and 3 p.m.
The heaviest winds of the day preceded the center of the storm, with the strongest gust — 84 mph — recorded Sunday morning at Big Black Mountain near Ramona. A gust of 54 mph was recorded at Camp Pendleton, and 44 mph at Petco Park in downtown San Diego.
Despite those brief blustery conditions, most urban areas in the county did not experience the sustained, strong winds typically associated with tropical systems. No gusts stronger than 40 mph were reported at the downtown airport, which had continued normal operations Sunday despite more than 200 flights being canceled by airlines.
The lack of sustained winds was chalked up to the weakening of the system and the speed with which it moved through the area. “The biggest impacts with Hilary were definitely the rainfall amounts,” Adams said.
With 1.82 inches of rain at San Diego International Airport, Sunday set a new record for the city’s wettest August day on record, according to the National Weather Service. It also marked the rainiest day in the city in more than six years, since 2.34 inches fell at the airport on Feb. 27, 2017, Adams said.
While Mount San Jacinto in Riverside County recorded the most rain in Southern California at 11.74 inches, Ranchita set the high mark for San Diego County with 7.38 inches, followed by Mount Laguna with 7.11 inches.
The National Weather Service said new August rainfall records were also set at Cuyamaca, with 4.11 inches; Escondido, with 2.66 inches; Oceanside Harbor, with 2.38 inches; Vista, with 2.12 inches; Ramona, with 2.03 inches; and El Cajon, with 1.86 inches.
The previous records were set Aug. 17, 1977, when a post-hurricane storm named Doreen slammed the region.
Sunday’s heavy rainfall caused some flooding and falling rocks on stretches of highways and interstates across the county.
The mudslides and rockslides largely occurred in rural areas in eastern and northeastern San Diego County, including on Interstate 8 near the boundary with Imperial County, where crews continued to work Monday clearing boulders and debris that shut down eastbound lanes. Crews were using jackhammers and other heavy equipment to break up the rocks, while geotechnical personnel were on site to scale and survey the slide area to make sure the road was safe.
Dargan, the city’s chief operating officer, said city crews worked “around the clock” to respond to damage on roads, fielding 147 reports of fallen trees and branches across the city, as well as a report of a sinkhole in the Miramar area.
“I’m thankful we did not receive any major catastrophe, no major damage to our facilities,” he said.
A little after sunset on Sunday, swift-water rescue crews from the San Diego Fire-Rescue Department aided 13 people whose encampment flooded in the Morena neighborhood, helping the group walk out of knee-deep water in the riverbed. A Cal Fire San Diego captain said firefighters performed two non-injury, minor rescues Sunday in desert communities for homeowners worried about flooding.
San Diego Gas & Electric officials said they didn’t see the number of outages they were expecting. “We were staffed up and ready,” SDG&E spokesperson Alex Welling said Monday morning.
By 4 p.m. Sunday, SDG&E reported as many as 39,000 customers had lost electricity at some point during the day. But Welling said that 38,000 later regained power, and the average time for restoration was about one hour.
Most of the outages were due to high winds or fallen tree branches striking power lines and occurred in the eastern and northern parts of the county.
“We didn’t see the number of outages that we had expected to see so being able to have all that extra crew of staff ready to go, I think, lent a hand to being able to restore power so quickly,” Welling said.
The Tijuana River was one area where the storm’s impact was apparent. The U.S. International Boundary and Water Commission said Monday that 1.8 billion gallons of untreated wastewater were flowing down the Tijuana River — more than four times as much as when the remnants of Tropical Storm Kay struck the area last September.
“It looks like a bomb went off of trash in the floodplain of the river,” Imperial Beach Mayor Paloma Aguirre said Monday. Aguirre said it was frustrating that Gov. Gavin Newsom was in town this weekend to declare an emergency ahead of Hilary’s arrival, but has yet to do so to address the yearslong battle to end the flow of sewage from Tijuana into local beaches.
San Diego Mayor Todd Gloria also proclaimed a local emergency Sunday, and the City Council voted 7-0 on Monday during an emergency meeting to approve the declaration, which will enable the city to seek state and federal emergency assistance funds.
“I want to thank the public for doing their part,” Councilmember Raul Campillo said during the meeting. “I saw lots of acts of neighborliness to make sure that people were taken care of, doing their part to make sure people were helping stay informed. It brought out the best in San Diego.”
At the news conference earlier in the day, Gloria had also thanked San Diegans for staying home and taking precautions.
“By doing so, what you managed to do is to reduce the need for emergency services,” Gloria said.
In an email Monday, San Diego Unified School District Superintendent Lamont Jackson thanked parents for being understanding about delaying the first day of the new school year, which had been scheduled for Monday. He said staff spent the day evaluating the district’s facilities and making repairs to minimal damage, and the district would be ready to welcome students back on Tuesday.
Borrego Springs Unified School District, which postponed its first day, was also planning to start classes Tuesday.
Though the storm did not do as much damage as expected, officials agreed the preparation was warranted.
“This is what I hoped for, but hope is not a plan,” Chris Heiser, director of the city of San Diego’s Office of Emergency Services, said during the joint city-county news conference. “I don’t control the weather, no one does, but you have to make decisions based on ... science and the best information you have at the time. It’s easier to back down from something than to school up for something.”
Staff writers David Hernandez, Rob Nikolewski, David Garrick, Tammy Murga and Caleb Lunetta contributed to this report.
4:57 a.m. Aug. 22, 2023: This story was updated with additional information.
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