06/322 AM.
Temperatures will remain near to slightly below normal through at least early next week as a series of low pressure systems move through the region. Low clouds and fog will cover most of the coast and valley locations through at least mid morning, clearing to near the beaches each afternoon. A warming trend is expected later next week.
(Sat-Tue), 06/722 PM.
Upper level trough pushing through northern and central California today, continuing strong onshore flow near the surface. This resulted in a deeper marine layer this morning with a cooling trend in most areas. In addition, onshore winds gusting between 25 and 40 mph remain common across the interior this afternoon and evening. The upper trough will continue to push through the region on Sunday. leading to lowering heights, and a further deepening of the marine layer, around 3500 feet for LA basin, and 1500-2000 feet across the Central Coast. The deepening marine layer will likely lead to areas of drizzle, especially for the LA county coastal slopes and foothills. In addition, there will likely be a delay in clearing for coast and valleys and lead to slightly cooler temperatures on Sunday.
By Monday high pressure starts to be build in from the west. the marine layer will begin to shrink with progressively earlier clearing times next week. Temperatures will be gradually warming as well, especially inland, but generally staying in the 80s in the valleys and 90s in the far interior.
Gusty sundowner winds are expected to make a return on Monday evening and Tuesday evening, with the strongest winds likely focused across western portions from Gaviota to San Marcos Pass. These areas have the potential to see gusts between 35 and 45 mph, with isolated gusts to 50 mph possible near Gaviota. As a result, wind advisories may be necessary as we draw closer.
(Wed-Sat), 06/230 PM.
High pressure is expected to strengthen across the eastern Pacific and California at least through Wednesday. This will bring at least some warming to most areas, but definitely favoring the interior areas like the Antelope Valley and interior SLO and Santa Barbara Counties which will be mostly immune to any onshore influence. In those areas there is 60-80 percent chance of 100 degrees or higher by the end of next week. Coastal valleys will warming as well but the latest ensemble pressure gradients suggest at least a 5-7mb onshore flow each afternoon which should keep warmer valley highs in the low to mid 90s and Downtown LA and other intermediate areas between the coast and valleys in the in the 70s to lower 80s. Night and morning low clouds and fog are expected to be a daily occurrence across all coastal areas next week as well as most coastal valleys through at least mid week and possibly beyond depending on the strength of the high.
Sundowners are expected to weaken by Wednesday, but possibly returning next weekend.
06/2350z.
At 2345Z at KLAX, the marine layer was 2000 feet deep. The top of the inversion was 3200 feet with a temperature of 20 degrees Celsius. For 00Z TAF package, high confidence in forecasts for KWJF, KPMD and KPRB. For all other sites, moderate confidence in forecasts due to uncertainties with behavior of the marine layer. Timing of flight category changes could be +/- 3 hours of current forecasts.
KLAX, Moderate confidence in 00Z TAF. Another early arrival of MVFR cigs expected this evening. 10 percent chance of cigs lingering through Sunday afternoon. No significant easterly wind component is expected.
KBUR, Moderate confidence in 00Z TAF. Timing of flight category changes could be +/- 3 hours of current forecast.
06/823 PM.
For the Outer Waters, moderate to high confidence in current forecast. Through Thursday, high confidence in a combination of Small Craft Advisory (SCA) level winds and seas. Additionally, there is a GALE WARNING over the two northern outer zones through late tonight, and a 60-80% chance of GALE force winds across these zones again Sunday late afternoon through late Sunday night. Monday and Tuesday, there is a 30-40% chance of Gale force winds during the same time period, with the best chances on Monday. SCA winds are likely to persist through Wednesday night, then weakening on Thursday.
For the Inner Waters north of Point Sal, high confidence in current forecast. Today through Wednesday, SCA level wind are expected, mainly in the afternoon and evening hours, with seas near or above SCA levels. On Thursday, winds and seas are expected to remain below SCA levels.
For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. For a majority of the southern Inner Waters, high confidence in winds and seas remaining below SCA levels through Thursday. The only exception will be the western half of the Santa Barbara Channel, where there is a 40-60% chance of SCA level winds Sunday through Tuesday, mainly in the late afternoon and evening hours.
Ca, NONE. PZ, Small Craft Advisory in effect until 3 AM PDT Monday for zones 645-676. (See LAXMWWLOX). Gale Warning in effect until 3 AM PDT Sunday for zones 670-673. (See LAXMWWLOX). Gale Warning in effect from 3 PM Sunday to 3 AM PDT Monday for zones 670-673. (See LAXMWWLOX).
