15/257 AM.
Highs today will be near normal, except for above normal across the deserts. This weekend temperatures will be cooler, followed by a warming trend starting Monday. Gusty winds are expected at times along the Central Coast, and across the mountains and deserts through the weekend, strongest on Saturday. Hazardous seas will impact the coastal waters over the next several days.
(tdy-Sun), 15/200 AM.
Overall, latest models exhibit good synoptic agreement through the short term period. At upper levels, broad northwest flow will prevail today, then an inside slider will drop into the Great Basin on Saturday/Sunday. At the surface, moderate onshore flow will prevail today, followed by moderate to locally strong northwesterly flow develops tonight through Sunday.
Forecast-wise, main concern in the short term will be the winds, more specifically the northwesterly winds. Current models remain very consistent, indicating moderate northerly offshore gradients and some decent upper level support. So, will expect northwesterly winds to increase during the day today across the usual spots (I-5 Corridor, northwestern Antelope Valley and the Santa Ynez Range) and continue through Sunday (with tonight and Saturday likely the strongest time period). In these areas, high resolution ensembles indicated at least a 70% chance of advisory- level gusts (40-55 MPH) and even a 20% chance of warning-level gusts (60+ MPH). Additionally, the Central Coast will likely also experience advisory-level gusts (30-40 MPH) on both Saturday and Sunday. Future shifts will likely need to issue various wind products.
Other than the winds, no significant issues are expected. With the upper level pattern, the marine inversion will remain on the deep side, but the increasing northwesterly flow will help to limit the areal extent of the marine layer stratus. So, somewhat low confidence in the current stratus forecast through the weekend. Other than any stratus west of the mountains, skies should remain mostly clear through Sunday.
As for temperatures, will expect near persistence temperatures today. However for Saturday and Sunday, there will be some cooling area- wide as the inside slider brings in some colder air to the region.
(Mon-Thu), 15/202 AM.
For the extended, models remain in decent agreement with the upper level pattern. Broad cyclonic flow is forecast to continue the period with a gradual increase in H5 heights. However at the surface, the models differ with the ECMWF and its ensembles indicate weak diurnal flow while the GFS and its ensembles indicate persistent weak to moderate onshore flow.
Forecast-wise, either model forecast indicates continued dry conditions for the region through next week. There will be some amount of marine layer stratus clouds each day, but the areal coverage will be at the whims of the surface gradients. Other than any marine layer stratus, skies should remain mostly clear through the period.
With this overall pattern, a warming trend can be expected for the area through the week. However if the ECMWF is correct with its surface pressure gradients, temperatures west of the mountains could be warmer than currently forecast.
15/1218z.
At 0725Z at KLAX, the marine layer was 1700 ft deep. The top of the inversion was at 4900 ft with a temperature of 18 C.
High confidence in VFR TAFs for KPMD and KWJF.
Moderate confidence in remaining TAFs. Timing of CIG/VSBY restrictions may be off +/- 2 hours and flight minimums off by one category. Chance there is a 30% chance of VSBY 1-3SM at KSBP from 13Z-16Z Fri.
KLAX, Moderate confidence in TAF. Cigs may clear between 19-23Z, however there is a 20% chance that MVFR cigs will persist all day. There is a 15% chance of east wind component reaching 6 kts 14Z-16Z Friday.
KBUR, Moderate confidence in TAF. Cigs may clear between 17Z-19Z, and may reform between 06Z-12Z Sat. No wind issues expected.
15/127 AM.
GALE WARNINGS are in effect for the inner waters along the Central Coast, all the outer waters, and the Santa Barbara Channel this weekend. Please refer to MWWLOX for further details.
For the outer waters from the Central Coast to San Nicolas Island, high confidence forecast. Winds will continue to increase to GALE FORCE levels today, becoming high-end, STRONG GALES over the weekend. Local STORM FORCE gusts are possible late Saturday afternoon into evening. SCA level seas will continue to build through the weekend, becoming large 10-15+ foot steep seas.
For the inner waters along the Central Coast, Small Craft Advisory (SCA) level seas will continue through the weekend. After a brief lull in winds this morning, winds will increase to high-end, STRONG GALE FORCE levels this afternoon and continue through Sunday evening.
For the inner waters south of Point Conception, The GALE WATCH has been converted to a GALE WARNING for the Santa Barbara Channel for Saturday afternoon through late night, with a high chance of GALE FORCE winds again Sunday afternoon and evening. For the southern inner waters adjacent to the L.A. Coast, SCA level winds are possible across the western portion each afternoon and evening over the weekend.
These dangerous sea conditions could capsize or damage small and large vessels. Mariners should adjust plans NOW to remain in safe harbor.
15/127 AM.
A combination of strong winds, large seas, and moderately high evening high tides may lead to high surf with coastal flooding possible this weekend. High Surf advisories and Beach Hazard statements have been issued across the entire coastline. Please refer to CFWLOX for more details for your area.
In general, hazardous surfing and swimming conditions are expected. Minor beach erosion and coastal flooding is possible, mainly during the evening high tides.
Ca, High Surf Advisory in effect from 3 PM this afternoon to 9 AM PDT Monday for zones 340-346. (See LAXCFWLOX). Wind Advisory in effect from 3 PM to 9 PM PDT Saturday for zones 340-341-346>348. (See LAXNPWLOX). Wind Advisory in effect from 3 PM Saturday to 9 AM PDT Sunday for zones 349-351>353. (See LAXNPWLOX). Beach Hazards Statement in effect from Saturday afternoon through Monday morning for zones 349-350. (See LAXCFWLOX). High Surf Advisory in effect from 3 PM Saturday to 9 AM PDT Monday for zone 354. (See LAXCFWLOX). Beach Hazards Statement in effect from Saturday evening through Monday morning for zones 362-366. (See LAXCFWLOX). Wind Advisory in effect from 9 PM this evening to 9 AM PDT Sunday for zones 376>378. (See LAXNPWLOX). Wind Advisory in effect from 9 PM this evening to 11 PM PDT Sunday for zones 381-383. (See LAXNPWLOX). Wind Advisory in effect from noon to 11 PM PDT Sunday for zone 382. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 3 PM PDT this afternoon for zones 645-673. (See LAXMWWLOX). Gale Warning in effect from 3 PM this afternoon to 9 PM PDT Sunday for zone 645. (See LAXMWWLOX). Gale Warning in effect from noon Saturday to 5 AM PDT Sunday for zone 650. (See LAXMWWLOX). Gale Watch in effect from Saturday afternoon through late Saturday night for zone 655. (See LAXMWWLOX). Gale Warning in effect until 3 AM PDT Monday for zone 670. (See LAXMWWLOX). Gale Warning in effect from 3 PM this afternoon to 3 AM PDT Monday for zone 673. (See LAXMWWLOX). Small Craft Advisory in effect until 6 PM PDT this evening for zone 676. (See LAXMWWLOX). Gale Warning in effect from 6 PM this evening to 3 AM PDT Monday for zone 676. (See LAXMWWLOX).
