A cold Pacific storm out of the Gulf of Alaska took aim at the Southland Wednesday, threatening a wet afternoon commute Thursday, sharply colder temperatures, and whiteout conditions on mountain roads, National Weather Service forecasters said.
The storm is expected to produce widespread showers Thursday, when there also will be a slight chance of thunderstorms, some of which could produce small hail, according to an NWS advisory.
Rainfall totals resulting from the storm are expected to be up to a half- inch in coastal, valley and desert areas and up to an inch in the foothills and mountains, according to the NWS.
The storm will cause the snow level to fall to its lowest point so far this season, according to the advisory. It will start at 5,000 feet this afternoon and drop to between 4,000 and 3,500 feet by Thursday morning, likely leaving snow on roadways, including Interstate 5 through The Grapevine.
Between three and six inches of snow is expected above 5,000 feet, although between six and eight inches is possible, according to the advisory.
"Light accumulations are expected down to near 4,000 feet, including the Tejon Pass," it said. "The combination of wet snow and low temperatures in the mountains could create a dangerous situation for campers and outdoor enthusiasts who are not prepared ..."
Wednesday's forecast called for winds of between 15 and 25 miles per hour in mountain areas, gusting to 45 mph. A winter weather advisory warning of difficult travel conditions, caused in part by blowing snow and a resulting loss in visibility, will be in effect in the San Gabriel Mountains for 24 hours starting at 4 this afternoon.
The Seven-Day Outlook for South Pasadena
- Thursday - Showers, mainly before 10am. High near 58. South southeast wind 5 to 10 mph. Chance of precipitation is 80%.
- Thursday Night - A 20 percent chance of showers before 10pm. Partly cloudy, with a low around 47. South southwest wind around 5 mph becoming calm in the evening.
- Friday - Mostly sunny, with a high near 58. North wind around 5 mph becoming west southwest in the morning.
- Friday Night - A 20 percent chance of showers. Mostly cloudy, with a low around 49. West southwest wind 5 to 10 mph becoming south southeast in the evening.
- Saturday - A 20 percent chance of showers before 10am. Mostly sunny, with a high near 61.
- Saturday Night - Partly cloudy, with a low around 48.
- Sunday - A chance of rain. Partly sunny, with a high near 62.
- Sunday Night - A slight chance of showers. Mostly cloudy, with a low around 49.
- Monday - Mostly sunny, with a high near 66.
- Monday Night - Partly cloudy, with a low around 52.
- Tuesday - Mostly sunny, with a high near 64.
- Tuesday Night - Partly cloudy, with a low around 52.
- Wednesday - Mostly sunny, with a high near 64.