A growing tropical storm in the eastern Pacific Ocean is forecast to move into the southwestern United States, bringing a potentially wet and cool weekend to Las Vegas.
Hilary, which strengthened from a tropical storm to a hurricane on Tuesday, could drop significant precipitation in the region from southern California to Arizona beginning late Saturday, according to the National Weather Service.
“Our best chances for rain are Sunday through Monday,” said Meteorologist Jenn Varian. “We have a forecast of widespread rain for the whole weekend.”
Of particular concern are Death Valley National Park and the 93,000-acre York fire late last month that started in California’s Mojave National Persevere and crossed into Nevada, Varian said.
“It would take very little rain there” for flash flooding to occur, he said.
In addition to the expected rainfall, temperatures will drop considerably. Highs of 92°F are forecast on Saturday and near 80°F on Sunday. On Monday it could reach 86°.
The current forecast for Las Vegas calls for a 70 percent chance of rain on Saturday, increasing on Sunday and Monday.
“We see it increasing every day,” Varian said.
Showers and thunderstorms are in the forecast through Wednesday.
Floods in Arizona, California and Mexico
As Hillary strengthens off the southwestern coast of Mexico and moves northwestward, concerns are growing about its potential impact on the southwestern United States, primarily in the form of flash flooding. The storm is forecast to become a hurricane later this week.
According to AccuWeather, flash flooding is a concern in the mountainous regions of western Mexico, California and western Arizona, especially prone to landslides.
Any heavy rain brings the possibility of flash flooding, falling debris, and washed out roads, along with rapidly rising waters.
Impact scenarios
A more easterly track could bring heavy rain and widespread flooding to the southwestern United States and western Mexico, while a westerly track could limit heavy rain to localized areas. Similarly, damaging winds would be more pronounced on an easterly track, while a westerly track would likely rid the region of such wind effects, according to AccuWeather.
Although Hilary is expected to remain offshore, localized damaging wind gusts could still affect parts of Baja California Saturday through Monday. Additionally, the western coast of Mexico through southern California should anticipate high swells and swells due to the influence of the storm.
Rare storms in California
Although not currently forecast, a landfall in southern California is not completely ruled out. If it did occur, it would be very rare, only a few times in history.
Southern California has seen notable tropical cyclones throughout history, such as the unnamed 1858 hurricane that hit San Diego. In addition, the El Niño of 1938-1939 brought four tropical cyclones with substantial rainfall to the region. Hurricane Kathleen in 1976 and Hurricanes Linda and Nora in 1997 also left their mark with torrential rains and high winds.
