08/114 PM.
It will be a little warmer today. Cooler conditions arrive Thursday followed by a chance of rain and thunderstorms Friday and over the weekend.
(tdy-Sat), 08/242 PM.
Most coast and valleys warmed up today at least a couple degrees with a weaker onshore flow and high pressure aloft. The most significant warming was along the Central Coast where temperatures were about 10 degrees warmer overall with some inland areas as much as 15 degrees warmer.
A cooling trend will begin Thursday as high pressure gets nudged to the east due to an advancing upper low over the eastern Pacific. Increasing morning low clouds and fog are expected along the coastal areas tomorrow, then reaching some of the coastal valleys Friday morning as the marine layer deepens. By Friday most areas will be at least 10 degrees cooler than today with highs mostly in the 60s to lower 70s.
A couple of low pressure systems are expected to move through California Friday and through Monday. Models are having some difficulty with the tracks and timing of each storm so overall confidence remains low on specific timing and rain amounts. There remains some potential for thunderstorms just about anywhere, though probably a better chance along the Central Coast where the colder air aloft will be. Some models are driving the colder air into LA/Ventura Counties but definitely less confident in that outcome. And the 12z ensembles are starting to show more intensity with the second system than the first, likely a result of the colder air shifting farther south. Expecting to see more model convergence over the next day or two that will hopefully provide more clarity on the situation. Precipitation will will be very showery in nature, which is typical with spring storms. So rainfall will be very much off and on, sometimes more off than on. It won't be a total washout weekend by any means, but there still could be some periods of heavy rain, and even snow in the mountains above 5000-6000 feet. But providing more specifics on timing and amounts may not come til Friday or even later. In short, it will be a mixed bag of weather this weekend, periods of showers (possibly heavy) as well as periods of dry, sunny conditions.
(Sun-Wed), 08/227 AM.
The weekend will be cloudy, cool and showery. Friday night's trof will exit the area Saturday morning. Hot on its heels, however, will be an even colder (534 dam) upper low that will sweep into the area and transverse the state by late Sunday. This cold, dynamic and unstable system will bring showers and a chc of TSTMs to the area. On average this system will produce about a half inch of rain over the 2 day period. Rainfall amounts, however, will likely not be too homogeneous due to the convective nature of the system. Some area may only see a quarter inch of rain, while others could see an inch or more. Most rainfall rates will be between 0.25 to 0.75 in/hr but higher rates will be possible under any TSTM that develops. Snow levels will fall to about 6000 ft and several inches of snow is possible above that elevation. Max temps both days will only be in the 60s or 4 to 8 locally 10 degrees blo normal.
There is some chc of lingering showers Sunday night, but by Monday dry NW flow will set up over the area. Both Monday and Tuesday will have mostly clear skies with rebounding temperatures (2 to 4 degrees Mon and 3 to 6 degrees Tuesday).
08/1736z.
At 1655Z at KLAX, the marine layer was 1100 ft deep. The top of the inversion was at 2100 ft with a temperature of 19 C.
Overall, moderate confidence in 18Z TAF Package. Timing of CIG/VSBY restrictions may be off +/- 2 hours and flight minimums by one category.
KLAX, Moderate confidence in TAF. Arrival and clearing times of IFR to low-end MVFR CIGs (007-012) should be accurate within +/- 2 hours from current forecast. There is a 30% chance east wind component reaches 7-8 kts between 09/08Z-16Z.
KBUR, High confidence in VFR TAF.
08/123 PM.
GALE Watch for Santa Barbara Channel (PZZ650) has been cancelled. However, localized GALE force wind gusts are still possible near Santa Cruz Island late this afternoon through this evening.
GALE Watch for the waters between Santa Cruz/Rosa and San Nicolas has been upgraded to a GALE Warning which is in effect this evening through the overnight hours.
All other small craft advisories appear to be on track. Refer to MWWLOX for details.
A storm system with showers and the potential for thunderstorms is expected to move across the coastal waters starting Thursday night lasting through the weekend.
Ca, NONE. PZ, Small Craft Advisory in effect until 10 PM PDT this evening for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 11 PM PDT Thursday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect from 6 PM this evening to 3 AM PDT Thursday for zone 655. (See LAXMWWLOX). Small Craft Advisory in effect until 11 PM PDT this evening for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 11 AM PDT Thursday for zone 673. (See LAXMWWLOX). Small Craft Advisory in effect until 3 PM PDT this afternoon for zone 676. (See LAXMWWLOX). Gale Warning in effect until 3 AM PDT Thursday for zone 676. (See LAXMWWLOX).
