The last of this week’s Pacific storms is poised to strike the Southland Friday, bringing a chance of rain Friday morning, a virtual certainty of rain Friday afternoon and snow at relatively low elevations Saturday, the National Weather Service said.
The rain will last through Saturday evening, according to an NWS statement. Temperatures, meanwhile, will remain below normal through Sunday, then warm to normal levels through midweek next week.
“A gradual warming and drying trend is expected Sunday through Tuesday, then another storm is forecast to affect the area next Wednesday through Friday,” the statement said.
In the meantime, scattered showers Saturday generally will produce between a quarter-inch and a half-inch of rain at lower elevations and between a half-inch and an inch in the mountains and foothills, according to the statement. The rain is expected to fall mostly at a rate of only a quarter inch per hour or less, but higher amounts are possible Saturday afternoon and evening if thunderstorms develop.
Over the San Gabriel Mountains, there will be a “very slim chance of a thunderstorm” because of “a slightly unstable air mass and cold air aloft,” according to the NWS statement, which stressed that the chances are low. And even if thunderstorms materialize, theoretically generating enough rain to trigger mud flows and rock slides over slopes that wildfires have stripped of vegetation, they should be moving fast enough to stave off any real risk, the NWS said, explaining why it is not immediately issuing flash flood watches.
The snow level in the San Gabriel Mountains is starting out at 5,000 feet Friday and will drop to between 3,000 and 4,000 feet Saturday, the NWS said. Less than six inches of snow is expected to accumulate but “there could be some impacts to Interstate 5 over the Grapevine Saturday, especially in the afternoon and evening,” the statement said.
A winter weather advisory denoting challenging mountain travel conditions will be in force from noon Friday until 5 a.m. Sunday in the San Gabriel Mountains in L.A. and Ventura counties, the NWS said, stressing that Interstate 5 over the Grapevine, Highway 2 and Highway 33 in Ventura County likely will be affected by snow.
After that, periods of moderate to heavy rain are possible Wednesday and Thursday and “could pose a threat to burn areas,” according to the NWS.
The NWS forecast rain in L.A. County Friday and highs of 43 degrees on Mount Wilson; 55 in Lancaster; 56 in Palmdale; 57 in Saugus; 59 in Avalon, Burbank and San Gabriel; 60 in Pasadena; 61 in Woodland Hills and at LAX; and 62 in Long Beach and Downtown L.A. Temperatures will be a degree or two colder Saturday amid partly cloudy skies, although showers are forecast in Saugus and snow showers on Mount Wilson. Then, on Sunday, temperatures will climb two or three degrees, still amid partly cloudy skies, then rise by five or six degrees on Monday abd by another two degrees or so Tuesday. Temperatures will remain in the low 70s Wednesday despite the return of the rain, which is also forecast Thursday.
Partly and mostly cloudy skies were forecast in Orange County, along with highs of 58 in San Clemente; 61 in Newport Beach; 62 in Laguna Beach and Mission Viejo; 63 in Yorba Linda, Fullerton and Irvine; and 64 in Anaheim. No rain is forecast in Orange County until Thursday. Until then, Orange County highs will remain in the low to mid 60s.
The expected rainfall totals resulting from the Southland’s three storms this week will be .93 inch in Beverly Hills and 2.6 inch in downtown L.A., said NWS weather specialist Stuart Seto.
For the month, Downtown has had 1.38 inches, which is within .09 inch of normal, he said. But for the season so far — from Oct. 1 to last night — the figure is a dismal 3.30 inches, compared to the normal, which is 12.42 inches, he said.
—City News Service