Hurricane Hilary could bring more than a year's worth of rain to Palm Springs area

The National Weather Service says Coachella Valley residents should prepare for the impacts of Hurricane Hilary, which will move into the valley this weekend after making landfall in Mexico and could dump more than a year’s worth of rain in areas.

NWS San Diego Meteorologist Miguel Miller said the service is starting to narrow down the potential track of the storm that is now expecting to bring around five inches of rain to Palm Springs.

However, other areas will likely see even more rain, with six inches expected in Thermal and seven to nine in the San Jacinto Mountains, although Miller said he expects some mountain spots will see even greater totals.

Hurricane Hilary live updates: Palm Springs, Coachella Valley under tropical storm watch

To put things in perspective, during the most recently completed water year lasting from Oct. 1, 2021 to Sept. 30, 2022, Palm Springs received just 2.06 inches of rain, which Miller noted constituted a dry year.

So far in the current water year, Palm Springs has received just 3.76 inches, meaning that Palm Springs will likely more than double its total from the last 10-plus months in just a few days.

Rain to begin Saturday night

The National Hurricane Center said Thursday that Hilary is strengthening rapidly and expected to develop into a “major hurricane” over the course of the day. The center of Hilary is now expected to approach the Baja California peninsula over the weekend, with Hilary expected to arrive in the valley as a tropical storm.

Miller said the valley will start to see impacts in the form of some showers on Saturday, with rainfall likelier to become steadier across the valley by Sunday. He said Sunday night and Monday morning are expected to be “ground zero” for the heaviest rainfall, with the rain then expected to taper off by Monday night.

Miller said the storm will likely cause significant flooding impacts in the desert, although the extent of those impacts will depend on the rate of the rainfall. However, he said at least some of the rain is expected to fall in thunderstorms that will produce rapid bursts of rain which could lead to flash flooding. He also said the Whitewater River will likely flood as rain comes out of the mountains.

Specific Storm Map:

Given the likelihood of at least some flooding, Miller said everyone should prepare for the storm by trying to clear out drainage areas near their home, particularly debris in low spots, to prevent floodwater from pooling where it shouldn’t and being pushed into homes. He also advised people to stay home on Sunday and Monday.

“If it seems safe when you go out, it could get worse in a hurry, so I wouldn’t tempt fate in that way,” he said.

Miller said that flooding impacts will be less severe if the rain falls evenly over multiple days, but that is not expected to happen as the rain will likely be concentrated in heavy bands and thunderstorms.

“We don’t expect the five to six inches in the valley to fall nice and evenly over three days,” he said.

He said the storm will also likely create winds of 50 to 60 mph.

Impacts won't be isolated to the desert areas either. Current National Weather Service forecast rainfall amounts for Saturday through Monday include:

Coast: 2 to 2.50 inchesValleys: 2.50 to 3 inchesMojave Desert: 3 to 4.50 inchesSan Bernardino County mountains: 4 to 6 inchesRiverside and San Diego County mountains: 4 to 8 inches, locally up to 10 inches on the eastern slopes of the mountainsLower deserts: 5 to 6 inches

Deluge could be reminiscent of Kathleen, Valentine's Day floods

While tropical systems impacting the Coachella Valley are rare, they aren’t unprecedented.

In September of 1976, Hurricane Kathleen made landfall in Baja California and later reached the Coachella Valley as a tropical storm. That storm swept into the desert with 75 mph winds and poured 18 inches of steady and often torrential rain in the valley.

The storm did nearly $4 million in damage in Palm Desert. The Desert Sun published this description of the scene: "The raging waters totally destroyed dozens of homes along Beverly Drive and Homestead before spreading over a broader field that eventually widened to nearly a mile when it hit the business district. Near its source, the boiling flood water was estimated to be at least four and maybe five feet high. It knocked down walls, carried freezers and refrigerators several blocks ... scores of homes were filled by several feet of mud."

More recently, Palm Springs famously received 3.69 inches of rain on Valentine’s Day in 2019, making for the wettest day in the city in 76 years. That torrent, which was caused by an atmospheric river, flooded and damaged roadways and even closed schools.

Paul Albani-Burgio covers breaking news and the City of Palm Springs. Follow him on Twitter at @albaniburgiop and via email at paul.albani-burgio@desertsun.com.

This article originally appeared on Palm Springs Desert Sun: Hurricane Hilary: Southern California could see over 5 inches of rain