09/154 PM.
Temperatures will rise to up to 15 degrees above early June normals by Wednesday. Minimal day to day temperature changes are expected through Friday, except for a large cool down Thursday on the Central Coast. Then a slow but gradual cooling trend is likely this weekend into early next week. Expect minimal marine layer clouds through at least Wednesday and potentially Thursday before becoming more widespread through the weekend.
(tdy-Fri), 09/154 PM.
June gloom will disappear for most of the area (save for the southern portion of the LA Basin) Wednesday and potentially Thursday thanks to offshore trends in pressure gradients. Then a rapid return of the gloom is expected Thursday night to most coasts and some of the lower coastal valleys.
The aforementioned offshore trends combined with a rapid increase in 500 mb heights the next 18 hours or so will bring about a fairly sharp increase in temperatures region-wide, with most noticeable warming across the Central Coast. Heat advisories have been issued for the interior coasts of Santa Barbara and San Luis Obispo counties for tomorrow, and tomorrow only. High temps are expected to reach 12-18 degrees above normal for these areas, elsewhere will commonly see up to 10 degrees above normal for early June. Increasing onshore flow Thursday on top of (or technically underneath) slightly weaker ridging will allow for most areas to cool down up to a few degrees south of Point Conception, with a much more dramatic decrease (4-8 degrees) for the Central Coast. Temperatures will then fluctuate +/- 3 degrees Friday, but more or less remain fairly similar to Thursday.
While temperatures remain the premier focus in the near term, gusty northwest to north winds have warranted wind advisories for Sundowners over the western Santa Ynez Range and over the I-5 Corridor tonight through Wednesday morning. Winds are generally expected to max out in the 20-30 mph with gusts to 50 mph range. Some gusty but sub-advisory level winds will be common elsewhere across interior mountains over night. Then fairly typical early June onshore flow is expected through Friday.
One notable possibility, albeit a very low (5% chance) possibility, is for a shower or thunderstorm to develop over southern portion of the forecast area, particularly the eastern San Gabriel mountains Friday afternoon through evening, with similar chances Saturday. PWATs will increase to near 1-inch as some moisture from the south is projected to surge into SoCal. There is also some instability in the area as a weak upper low meanders off the coast of Baja California, but most model projections favor any thunderstorm/shower activity to remain south and east of Los Angeles County.
(Sat-Tue), 09/154 PM.
As mentioned in the short term section, there exists a small chance for shower or thunderstorm activity over the eastern San Gabriel Mountains Saturday afternoon through evening.
Gradual and minor cooling is expected Friday into early next week across much of the area, but day-to-day changes will be less than noticeable. Persistent onshore flow will drive the daily cooling as ridging is favored to persist through the extended period.
June gloom should be in full force this weekend into early next week across the coasts and lower coastal valleys in the overnight through morning hours. While winds are generally not expected to be significant, there are some ensemble members suggesting increasing Sundowner wind activity towards the end of the weekend and early next week. This could scour out the marine layer in southern Santa Barbara and Ventura Counties.
09/1729z.
At 1633Z at KLAX, the marine layer was about 2100 ft deep. The inversion top was at 3300 ft with a maximum temperature of 17 C.
High confidence in VFR TAFs for KPMD and KWJF, but winds may be off by 5 kt at times.
Moderate confidence in remaining TAFs. Timing of flight category changes may be off +/- 3 hours. Most cigs that form are scattering out or clearing. There is a 15-25% chance of MVFR cigs at KSMO, and KLAX between 13Z-15Z Wed, and a 50% chance at KLGB.
KLAX, Moderate confidence in TAF. Timing of flight category changes could be +/- 3 hours of current forecast, and there is a 25% chance of BKN015 cigs between 13Z-15Z Wed. Any east wind component is expect to be less than 6 kt.
KBUR, High confidence in TAF.
09/223 PM.
For the Outer Waters, moderate to high confidence in current forecast. High confidence in a combination of Small Craft Advisory (SCA) level winds and seas through Wednesday. Localized gale force gusts will be possible over all of the outer waters late this afternoon and early evening. Otherwise, SCA winds are likely to persist through Wednesday night, with much weaker winds Thursday through Saturday.
For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. SCA level wind are expected through Wednesday, mainly in the afternoon and evening hours, with seas near or above SCA levels. Lighter winds are likely during the morning hours, then increasing again each afternoon. Thursday through Saturday, 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. There is a 40% chance for isolated Gale force gusts over the west portion of PZZ650 this afternoon and evening. For a majority of the southern Inner Waters, high confidence in winds and seas remaining below SCA levels through Friday. The exception will be the western half of the Santa Barbara Channel, with a SCA in effect through late tonight. Light winds are then expected Wednesday through Saturday.
09/247 PM.
A High Surf Advisory is in effect for beaches along Malibu through Thursday. As of 1 PM PSD, latest report from Zuma indicated swell height around 7 to 10 feet at 19 seconds. A Beach Hazard Statement remain in effect for the Ventura County Beaches through Thursday evening. A long period south swell will continue to move through the waters Today through Thursday, with swell height building to 3 feet nearshore. Periods around 20 seconds, decreasing to 15 seconds by Thursday. Surf is forecast to build to 4 to 7 feet with local sets to 7 to 10 feet along south facing shores of Los Angeles County Beaches, and 3 to 6 feet for Ventura County Beaches.
Hazardous surfing and swimming conditions are expected due to the building surf, along with strong rip currents.
Ca, High Surf Advisory in effect until 8 PM PDT Thursday for zones 87-362-366. (See LAXCFWLOX). Heat Advisory in effect from 10 AM to 7 PM PDT Wednesday for zones 341-347. (See LAXNPWLOX). Wind Advisory remains in effect from 7 PM this evening to 7 AM PDT Wednesday for zones 349-351-378. (See LAXNPWLOX). Beach Hazards Statement in effect through Thursday evening for zone 354. (See LAXCFWLOX). PZ, Small Craft Advisory in effect until 3 AM PDT Wednesday for zones 645-650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 5 PM PDT Wednesday for zone 673. (See LAXMWWLOX). Small Craft Advisory in effect until 8 AM PDT Wednesday for zone 676. (See LAXMWWLOX).
