Tropical Hurricane & Storm Hilary Devastates Parts of Mexico & California

Aerial shot of Dodgers Stadium in Los Angeles, California, after Tropical Storm Hillary dumped record amounts of rainfall on the area. The baseball stadium itself survived without much flooding, but the parking lot surrounding it became a virtual swimming pool after the rain. The Los Angeles city skyline can be seen in the background. Image: Alaaddin Nooraddin, screen capture from Video posted on Twitter/X

Hurricane Hilary appeared first on August 12 as a warm heat wave located in the Pacific Ocean, off the coasts of southern Mexico, Guatemala, and El Salvador. Within two days it had become a tropical depression and was heading west-northwest. On August 17, around 320 miles southwest of Manzanilla, Colima, it became a Category 1 hurricane.

Storm track for Hurricane/Tropical Storm Hillary in August 2023.  Image: Cyclonebiskit using NASA data and mapping tools. Public Domain

One day later, on August 18, charged by super-heated ocean temperatures which have characterized much of the world this year, Hillary had intensified to become a Category 4 Hurricane. Sustained winds rose to their highest for the storm that day, ratcheting up from 65 mph just a day earlier to 145 mph (230 km/h) in just 24 hours.

The hurricane twisted mostly northwards soon after, careening along the coast of  the Cabo San Lucas area of Baja California by August 19.

As it passed over cooler waters, Hillary shifted back down to a Category 1 hurricane by late Saturday. On Sunday, August 20, it made landfall as a tropical storm with 65 mph sustained winds at San Quintin, Baja California, roughly 215 miles south-southeast of San Diego, California.

The storm lost significant wind power after heading over land, but still managed to strike the San Diego, California area with winds only slightly diminished by that point and still providing torrential rains.

It then shifted direction again, turning more north-northeasterly, its core narrowly missing the center of Los Angeles. As of August 21, it had mostly moved on. It was still a powerful storm with tremendous rain capability, where it as of this article was beginning to drench the deserts just southwest of the California-Nevada border into a region northwest of Las Vegas.

As the storm neared, California Governor Gavin Newsom mobilized the state, declaring an emergency for Southern California. It ordered evacuations of Catalina Island, just west of Los Angeles, and issued flood warnings for over 25 million. Most of those took place in San Diego County, up through the deserts of Palm Springs, California, and east of Los Angeles proper. Schools, state and federal office buildings, and most companies were shuttered on August 20 and 21 as the worst of the storm made it through.

California’s Flood Operations Center deployed over 300,000 sandbags to address local flooding. The state’s Department of Forestry, on alert in part because previous wildfires had left many areas where trees and other natural groundcovers had burned away in past years, leaving the ground unprotected from the heavy rains to come. California’s Office of Emergency Services and the state National Guard were also sent out. Specialized ground crews were also brought in to address storm drain blockages in real time, deal with water supply interruptions, and to restore power which went out quickly in many parts of the region, though surprisingly just tens of thousands of people were directly affected for more than a few hours.

Hurricane Hillary, shown here as it reached its Cat 4 peak intensity on August 18, 2023. It had maximum sustained winds of 145 mph (235 km/h) and was located off the coast of Baja California at this point. Image taken by NOAA's GOES-16 Satellite's Advanced Baseline Imager (ABI). Image: NASA

Flash flood and mud landslide warnings were widespread as the storm reached its peak, with heavy flooding following quickly on the heels of those alerts. Downed trees and other debris swept up by the rain and still powerful winds caused many roads to be shut down.

9-1-1 emergency services were down in many areas throughout, making it necessary for emergency services to remain connected by other communications means, including satellite phones.

The worst of the flooding appeared in the desert regions not far from Los Angeles.

Palm Springs, a desert resort city located in the famed Coachella Valley in Riverside County, was one of the hardest hit. It received 3.18 inches of rain from the storm on August 20, breaking by over a factor of three the previous record single-day rainfall amount of just one inch. Within its boundaries, flooding and winds destroyed many homes, shut down power, and forced those stuck or hurt to communicate with 9-1-1 for the first time solely by text messaging.

Interstate 10, a major national highway which stretches all the way across the nation from Southern California to Florida, was covered by water, vegetation, and mud as of daylight on August 21. It was reopened to traffic, with drivers advised to proceed with caution, by late yesterday.

Highway 111, another major roadway in the area, had its northbound lanes also covered with mud. It too was shut down for some time.

In a televised interview yesterday morning, Grace Garner, the mayor of Palm Springs, said that Tropical Storm Hillary had created extensive havoc for her city and nearby areas than even the early warnings might have suggested. With some cities in the desert area receiving over a year’s worth of rain in a single day, the destruction and disruption would take considerable time to recover from.

“Right now we have flooding on all our roads,” she said in the interview. “There’s no way in or out of Palm Springs, and that’s the case for the majority of the Coachella Valley.”

Further, with the 9-1-1 emergency hotlines down, she said, “We’re all stuck.”

In nearby Palm Desert things were not much different.

“This storm has been unlike anything our community has faced before,” city officials there explained in a post on their Facebook page on August 20.

“We want to thank our residents, businesses, and members of the community for their patience as we work to clean up downed trees and mitigate flooding,” the post continued. “Not everything is a quick fix, but our team is doing our best to have Palm Desert up and running tomorrow.”

Further eastward in Death Valley, large temporary lakes have formed in that desert community. Death Valley National Park itself is closed for an indefinite time, as many roads within the park are impassable after standing water, flash floods, mudslides, and desert vegetation have covered them.

Normally neither tropical storms nor hurricanes reach Southern California with much intensity, mostly because the ocean waters are normally cold from the current that flows south from British Columbia. But with ocean temperatures soaring this year, it set the conditions for rapid storm intensification and much heavier-than-normal rainfall, boosted by the high moisture content in the area just above the surface of the sea.

“We’re seeing this increase in… severe weather events…not just in the number, but [also] the severity of these events,” said Federal Emergency Management Agency (FEMA) administrator Deanne Criswell in an interview made about the current storm.

With El Niño already warming ocean waters off the Pacific Coast to much higher temperatures than normal, equally or perhaps even more powerful tropical storms could become more common in Southern California in the future.

At the time of publishing, tropical storm Hillary is pummeling Nevada with road closures due to washouts and flooding but seems to be diminishing quickly. The governor of Nevada has followed the lead of California in declaring a state of emergency in advance.

Tropical Storm Harold is forecast to arrive into south Texas by midday today and expected to produce heavy rain, flash and urban flooding, tropical storm conditions, coastal flooding and tornadoes, but might bring some relief to the intense heat the region has been suffering.

It is all another reminder of what the climate crisis has ahead for all.

Those who want to know what the future likely holds might want to watch the following video: