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Southern California faces an unprecedented tropical threat as former Hurricane Hilary unleashes torrential rainfall and damaging winds across the region. The powerful storm slammed into Baja California Sunday before tracking north, making landfall again near Palm Springs by late afternoon. With Hilary poised to dump historic rainfall overnight across already saturated areas, officials warn of potentially catastrophic flash flooding and urge residents to prepare for this extremely dangerous tropical system.
Sustained winds of 50mph and wind gusts over 60mph pummeled Palm Springs Sunday evening as Hilary's center crossed the area. Packing the punch of a moderate hurricane, the potent storm is forecast to sweep east overnight across Southern California into Nevada and Arizona, triggering widespread flooding and tornado threats before dissipating by Monday morning.
Riverside, San Bernardino, Los Angeles, and San Diego counties have already declared emergencies, with mandatory evacuations ordered in many communities in Hilary's path. Visibility will be extremely poor and roads quickly inundated during the overnight deluge, creating dangerous, potentially life-threatening conditions. Residents are advised to shelter in place and avoid driving through flooded roads.
The National Weather Service warns some areas could witness over 10 inches of rain, more than their entire yearly average, within just hours. Hillside communities face the highest risk of mudslides and flash flooding, which often strike with little warning during intense downpours. Meanwhile, strong winds will down trees and power lines, causing widespread outages.
This could be the most significant tropical system to directly impact Southern California since 1939, when a rare storm brought similar hazards 80 years ago. With most tropical activity centered off Mexico's Baja Peninsula, Southern California is highly vulnerable to Hilary's effects, lacking modern storm preparations and infrastructure. Officials urge extreme caution through Monday as the region faces a dangerous night ahead.
Powerful Hilary Wallops Baja California before Turning North
The epic rains arrived on the heels of Hurricane Hilary's earlier landfall over Baja California, Mexico, bringing flooding and winds over 80mph. At least one drowning death was reported in the coastal town of Santa Rosalia amid extreme beach erosion and building damage. While downgraded to a tropical storm before hitting Southern California, Hilary remains capable of hurricane-force impacts as it interacts with land.
Packing previous wind gusts to 115mph offshore, Hurricane Hilary was the second hurricane of the active Eastern Pacific season. The storm rapidly intensified July 24-25 before weakening over cooler waters approaching Baja. However, abundant tropical moisture still feeds the system, fueling torrential rains as it moves north into the US Southwest.
Hilary is forecast to maintain 50mph winds into Monday morning as it crosses desert areas from Palm Springs to Las Vegas. Bands of intense rain are already developing, signaling the massive flooding threat ahead. Some locations may witness their entire yearly rainfall overnight, overwhelming drainage systems and turning roads into raging rivers.
State of Emergency Declared as Downpours Flood Roads
With Hilary poised to make US landfall Sunday, states of emergency were declared across Southern California Saturday night. Hardest hit areas are projected from San Diego County to Death Valley, where flash flood emergencies are possible. Evacuations were already ordered for many hillside neighborhoods at high risk of mudslides and debris flows.
Road closures due to flooding or damage have been reported from San Diego to Los Angeles ahead of the heaviest rains. Dramatic videos on social media showed cars stranded and tunnels filled with runoff. One Los Angeles area freeway became a raging river, nearly sweeping away trapped vehicles. With storm sewers overwhelmed, motorists are warned not to drive into flooded roadways.
Be Prepared! Charge Devices, Gather Supplies Before the Overnight Onslaught
Residents are advised to prepare now before night falls and the most dangerous conditions arrive. Charge cell phones and stock up on essential supplies like food, water, batteries and flashlights. Also clear yards of debris that could clog drainage areas and double-check evacuation routes if ordered to leave.
Have pets leashed and carriers ready in case of sudden evacuations. Move valuables off the floor upstairs if possible. Make sure gutters are cleared to prevent flooding damage. Gather rain gear, boots, gloves, blankets in case the power goes out overnight.
With intense rainfall after dark, avoid driving into standing water, which can be deeper than it appears and conceal washed out roads. Just 12 inches of fast-moving water can sweep away cars. If floodwaters quickly surround vehicles, abandon them and move to higher ground immediately.
Bookmark emergency alert and radar websites to monitor real-time conditions overnight. Have a battery-powered radio to receive updates if the power fails. Know if your area is prone to landslides or flooding and be ready to evacuate. Getting through the next 12 hours safely will require vigilance and preparation.
Southern California Faces First Tropical Storm Threat Since 1939
Unlike hurricane-prone states along the Gulf and East Coasts, Southern California has scant experience with tropical storms and their hazards. The last comparable event came in September 1939, when an unnamed storm moved north from Baja California into San Diego County.
The 1939 tropical cyclone brought 3 days of heavy rain that triggered widespread flooding and damage. Rivers jumped their banks, homes were destroyed, and several fatalities occurred. At the time, meteorologists had limited tracking and forecasting abilities compared to modern weather technology.
Today officials have the benefit of advanced satellite data and predictive models. A well-coordinated emergency response is also being mounted across the region. However, the population has grown over tenfold since 1939, meaning far more residents and critical infrastructure now lie exposed to potential disaster.
While not receiving direct hurricane strikes, Southern California is periodically affected by tropical remnants that have crossed Baja California like Hilary. In 1976 and 1984, decaying storms brought flooding rains and mudslides causing extensive damage. But Hilary will be making landfall at much stronger intensity, with its powerful rains targeting areas not used to tropical weather threats.
Preparing for the New Normal: Wetter Storms and More Flood Risk
Hilary underscores how a warming climate is bringing wetter storms and greater flood risk worldwide. As global temperatures rise due to increasing greenhouse gas emissions, the atmosphere holds more moisture, which condenses as heavier rainfall during storms.
Recent research has shown tropical cyclones are already slowing down more, allowing them to dump more rain locally rather than spread it out. Intense rainfall rates during hurricanes have increased significantly since the 1980s. Models predict this trend will continue as the world warms, regardless of greenhouse gas emission reductions.
For Southern California already plagued by cycles of drought and wildfires, massive rains from tropical weather add a new challenge. Hilary may offer a glimpse into the region's future, with authorities stressing the need to improve storm preparations and infrastructure before climate impacts worsen.
From upgraded dams and levees to better emergency plans, investments today could save lives and property when the next inevitable storm strikes. For now, Hilary requires Southern Californians' full focus through Monday morning as an unprecedented tropical threat looms.
Heed all evacuation orders and weather advisories to stay safe. Check on neighbors to ensure they are ready. With the worst conditions still ahead overnight, extreme caution and vigilance are paramount. But by working together and actively preparing, the region hopes to weather this rare tropical emergency.
Summarised from original article by Juliana Kim for - npr.org
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