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Hilary moves northward across the western U.S.



As AccuWeather meteorologists correctly predicted, Hilary brought historic rainfall and wind to Southern California this past weekend. Now the storm is moving northward, causing problems for the western U.S.

Key Highlights

Threats: Heavy rainfall, flash flooding, mudslides, damaging winds, power outages, road closures

Areas affected: CA, NV, AZ

When: Friday, August 18 – Tuesday, August 22

As accurately forecasted by AccuWeather meteorologists, Hilary brought unprecedented levels of rainfall and strong winds to Southern California over the weekend. By early Monday, Hilary was a tropical rainstorm, with its wind strength diminishing as it traveled to the Sierra Nevada region. AccuWeather For Business is warning companies in the area to prepare for significant impacts on operations.

Learn more about AccuWeather's Hurricane Warning Service

The remnants of Hilary will advance northward Monday, spanning from Nevada to Idaho and Montana and eventually progressing into Canada by Monday night. The intense rainfall now moves from Southern California to the Intermountain West. Even though the risk of heavy rainfall will dwindle across Southern California, the area will still experience life-threatening surf and rip current conditions. 


The track and impacts from Hilary represent an extraordinarily rare event, and significant flash flooding occurred in areas not accustomed to receiving heavy rain in August, including in and around Los Angeles and San Diego. Because of the heavy rain and flooding threat, Hilary is a 2 on the AccuWeather RealImpact Scale™ for the U.S. In contrast to the Saffir-Simpson Hurricane Wind Scale, which classifies storms by wind speed only, the AccuWeather RealImpact™ Scale is based on a broad range of important factors. In order to better communicate a more comprehensive representation of the potential impact of a storm on lives and livelihoods, the scale covers not only wind speed but also flooding rain, storm surge and economic damage and loss. Some of these hazards such as inland flooding and storm surge in many storms, result in more deaths and economic loss than wind.

Hilary impacts

Rain will wind down Monday across Southern California as the core of moisture associated with Hilary races northward. Flooding downpours can occur in parts of eastern Oregon, Idaho and western Montana today, where flood-prone areas such as burn scars may be at risk for rock and mudslides. 


Businesses in California and surrounding states will need to keep a close eye on this storm as it approaches and should: 

  • Determine hazards your location is most vulnerable to during a hurricane
  • Perform a vulnerability assessment of all equipment, processes and operations
  • Prepare for winds and flying debris to cut power, which may not be restored immediately
  • Stay away from floodwaters

AccuWeather For Business can help companies and communities better prepare for hurricanes and keep their employees and customers safer.

AccuWeather's hurricane tracking is 3% more accurate than the National Hurricane Center and 13% more accurate on the intensity of the hurricane winds along the path. For example, AccuWeather was the only source to forecast a 16-20’ storm surge ahead of the disaster in Ft. Myers from Hurricane Ian that killed over 100 people. Our competitors predicted 12-16 feet, leaving many businesses in the path of that dangerous storm surge. Also, the forecasts from AccuWeather Hurricane Experts are often initiated well before the National Hurricane Center and any other source, updated more frequently, and have 14 unique layers describing impacts such as rainfall, wind gusts, the risk to lives and property that are exclusively made available by AccuWeather.

Hurricanes are not just a problem along the coast; they can also impact businesses several hundred miles inland. Don't wait for an imminent hurricane or tropical storm to prepare your business for one. The message is clear: Start planning now. AccuWeather For Business has several tools to help you better prepare for tropical threats, including AccuWeather’s Hurricane Warning Service. Contact one of our experts today for a consultation.

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