Rain Heads To Palm Desert This Week: When And How Much Rain Will Fall?

PALM DESERT, CA —It's not a matter of if the storm is coming, but when and how much rain, according to meteorologists. The Inland Empire will be slammed by heavy rain and snow midweek as storms roll out of the Pacific aboard an atmospheric river, the National Weather Service forecasters said Monday.

"This plume of moisture is rather deep, so confidence is high that Wednesday, we'll get widespread rain spreading across the entire region," the National Weather Service said in a statement. "There may be some decrease in rain late Wednesday into Thursday morning. Then a second plume of moisture arrives Thursday with a more organized trough to provide a little more energy and precipitation output, lasting through Friday."

The chances of rainfall throughout the region are better than 80% Thursday to Friday, according to meteorologists. "Orographics will come into play with lifting over mountains, enhancing the rainfall there," the NWS said in a statement. "This will be especially effective in the mountains of San Bernardino County. Snow levels will be rising as the precipitation arrives. Some snow could fall at 5,500 feet Wednesday morning before the snow levels rise to over 7,000 feet Wednesday night and over 8,000 feet late Thursday."

The Weather Service cautioned that the strength of these low-pressure troughs is greater than what the region has experienced so far this winter.

"This will be definitely our wettest storm period in the past year," the agency said. "The deep moisture of both of these waves raises concerns for flooding, especially in recent burn scars."

No advisories had been posted as of Monday morning.

The NWS predicted 2 to 3 inches of rain likely in valleys and other lowlands west of the inland mountain ranges Wednesday to Friday, while desert locations may see anywhere from .5 to 1.5 inches over the same period.

"Snowfall above 8,000 feet could pile up to 18 inches or so, but less than 3 inches below 7,000 feet," according to the agency.

High temperatures in the Riverside metropolitan area Monday and Tuesday will top out in the mid-60s, with overnight lows in the low 40s, while from Wednesday to Friday, the highs will peak in the mid-50s, followed by lows in the mid-40s.

The temperature bands will be almost identical for the Coachella and Temecula valleys.

For the weekend, skies will clear, with mostly sunny conditions region-wide, and the mercury generally will climb back into the upper 60s and low 70s during daylight hours, dipping to around 40 at night, forecasters said.

In Palm Desert, here is your weather forecast for the week:

Monday
Sunny, with a high near 76. Southeast wind 5 to 10 mph.

Monday night
Mostly clear, with a low around 46. West wind around 5 mph.

Tuesday
Sunny, with a high near 69. North wind 10 to 15 mph becoming west in the afternoon. Winds could gust as high as 25 mph.

Tuesday Night
Partly cloudy, with a low around 46. West wind 10 to 15 mph, with gusts as high as 20 mph.

Wednesday
A chance of rain. Mostly sunny, with a high near 65. West wind 5 to 10 mph becoming east in the afternoon. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Wednesday Night
Rain likely, mainly after 4am. Mostly cloudy, with a low around 48. Chance of precipitation is 60%.

Thursday
Rain. High near 65. Chance of precipitation is 80%.

Thursday Night
Rain. The rain could be heavy at times. Mostly cloudy, with a low around 50.

Friday
Rain likely, mainly before 10am. Partly sunny, with a high near 65.

Friday Night
Partly cloudy, with a low around 47.

Saturday
Sunny, with a high near 72.

Saturday Night
Mostly clear, with a low around 50.

Sunday
Mostly sunny, with a high near 75.