Pasadena Faces Powerful Week-Long Series of Winter Storms Beginning Saturday

The first of a predicted series of strong, rain-laden, wind-whipped winter storms expected this week will arrive in Pasadena late Saturday afternoon, National Weather Service forecasters said.

The powerful atmospheric river will arrive after 4 p.m., ultimately bringing heavy rains and winds. This storm will be followed by showers and lowering snow levels in the mountains north of Pasadena throughout the week.

“Residents of southwestern California will generally awaken to the calm before the storm this morning,” NWS forecasters said.

NWS Wind Advisories have been issued for Los Angeles County beginning around daybreak on Sunday.

On Sunday, rain is expected across the entire region, and will be heavy at times, likely continuing to increase in intensity in most areas through the day. It may take much of the day for the heavy rain to reach all of Los Angeles County, according to forecasters.

Heavier rain will likely continue through Wednesday. A second wave of lesser intensity is expected Thursday through Friday next week.

Here is the National Weather Service forecast for the week, released at 3:48 a.m. on Saturday morning:

Today: A 30 percent chance of rain after 4 p.m. Mostly sunny, with a high near 59. East wind 5 to 10 mph becoming south in the afternoon. Winds could gust as high as 15 mph. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Rain likely, mainly after 10 p.m. Mostly cloudy, with a low around 45. East southeast wind 10 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Sunday: Rain. High near 58. Breezy, with an east southeast wind 20 to 25 mph, with gusts as high as 35 mph. Chance of precipitation is 80%. New precipitation amounts between three quarters and one inch possible.

Sunday Night: Rain and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Low around 48. Breezy, with an east southeast wind 15 to 25 mph, with gusts as high as 35 mph. Chance of precipitation is 90%. New rainfall amounts between 2 and 3 inches possible.

Monday: Rain and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 60. South southeast wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.

Monday Night: Rain and possibly a thunderstorm. Low around 47. Chance of precipitation is 90%.

Tuesday: Showers and possibly a thunderstorm. Some of the storms could produce heavy rain. High near 56. Chance of precipitation is 90%.

Tuesday Night: Showers likely and possibly a thunderstorm before 10pm, then rain likely, mainly between 10pm and 4am. Mostly cloudy, with a low around 43.

Wednesday: Rain likely, mainly after 10 a.m. Partly sunny, with a high near 59.

Wednesday Night: A chance of rain. Mostly cloudy, with a low around 42.

Thursday: A chance of rain. Partly sunny, with a high near 58.

Thursday Night: A chance of rain. Mostly cloudy, with a low around 44.

Friday: A chance of rain. Partly sunny, with a high near 59.