10/719 PM.
A couple storms will move through the area this weekend into Monday with showers and thunderstorms possible. The heaviest rain is likely to occur later Saturday into Sunday afternoon. Dry and warmer weather is expected the rest of next week.
(Fri-Mon), 10/737 PM.
***UPDATE***
The first of two storm systems has been producing rain over areas near/north of Point Conception today. Mainly light rain has fallen so far, with the exception of Rocky Butte (0.63") and a handful of mountain and foothill locations in Santa Barbara and San Luis Obispo Counties. There was a small chance of thunderstorms over the northern sections this afternoon, but that threat has ended. Mainly light scattered showers with minimal impacts are expected over the northern sections through Saturday afternoon. Additional rainfall through 5 PM will be 0.05 to 0.15 inch, mainly over the coastal hills and windward slopes. Many areas may see little or no rainfall.
While the northern counties will remain mostly cloudy and cool tomorrow, with highs in the 60s, further south Ventura and LA Counties will see highs in the mid 60s to low 70s, with partly cloudy skies for much of the area.
Gusty south to southwest winds this evening (gusts 30-40 mph over the interior) will decrease overnight into Saturday morning, then increase again in the afternoon and night. The winds will be strongest over the foothills and mountains, with gusts increasing from 25 to 30 mph in the afternoon to 30 to 40 mph Saturday night.
***From Previous Discussion***
The second upper low will move into northern California later Saturday night. Hi res models indicate increasing instability overnight into Sunday morning with around a 3-5 hour period of steady rain and possible thunderstorms moving through the entire forecast area. CAPE values of around 500j/kg will provide the necessary lift for convective activity, including brief heavy downpours, gusty winds, and possible lightning. Can't rule out a small tornado or waterspout as models are showing sufficient helicity in the lower layers.
Rain amounts expected to generally be a half to one inch, except locally higher in the mountains and along the Central Coast. Due to the convective nature of this storm, rain amounts could vary quite a bit, even over very short distances. Rain rates expected to top out around a quarter to half inch per hour, except very brief and isolated rates as high as 0.75" in the strongest storms.
A Winter Weather Advisory was issued for the higher mountains, mainly above 5000 feet. Snow levels will be around 7000 feet through Sunday morning, then lowering to around 5000 feet Sunday afternoon into Monday morning. Snow accumulations of up to 6 inches are possible above 7000 feet, and 1-3 inches as low as 5000 feet. Not expecting any snow accumulations on the Grapevine over Interstate 5, though there could be a mix of rain and snow early Monday morning.
Drying conditions expected by Monday afternoon, if not earlier.
(Tue-Fri), 10/146 PM.
Dry and warmer weather expected all of next week. Temperatures will warm 1-3 degrees each day. By mid week highs will be around 70 near the coast and near 80 inland. Possibly some light offshore flow developing Friday into next weekend.
11/0217z.
At 0005Z at KLAX, the marine layer was 1500 ft deep. The top of the inversion was at 2200 ft with a temperature of 15 C.
Moderate confidence in rain timing with a 30-40 percent chance of showers, and a 15% chance of thunderstorms for KSBP, KPRB, KSMX, and KSBA through the period. There is a 20-30% chance of showers for all other sites after 05Z. IFR to MVFR cigs/vsbys possible during -shra. For sites with MVFR cigs overnight , there is a 20% that conditions remain VFR for much of the period.
KLAX, Moderate confidence in TAF. There is a 20% chance of showers after 04Z, and there is a 20% chance of mostly VFR cigs through the period. No significant east wind component expected.
KBUR, Moderate confidence in TAF. There is a 20% chance of showers after 04Z.
10/803 PM.
A weak cold front will move across the coastal waters through Saturday morning bringing showers and a slight chance for a thunderstorm north of Point Conception.
A second system will arrive late Saturday into Sunday. This front will be stronger, bring numerous showers and a slight chance for thunderstorms across all waters. Potential hazards include: heavy downpours, dangerous cloud to ocean lightning, small hail, and erratic gusty winds. Boaters, especially those with small vessels should avoid these conditions.
Ca, Winter Weather Advisory in effect from 9 PM Saturday to 11 AM PDT Monday for zones 353-376-377. (See LAXWSWLOX). Winter Weather Advisory in effect from 3 AM Sunday to 11 AM PDT Monday for zones 378>380. (See LAXWSWLOX). PZ, NONE.
