17/1222 PM.
Steady cooling through Friday with below normal temperatures through the weekend. Ample low clouds each morning through the weekend, with patches of drizzle possible Thursday and Friday. Gusty onshore winds will impact interior areas through the week. A significant warming trend remains on track for next week with heat impacts expected.
(tdy-Sat), 17/1142 AM.
SoCal is currently situated underneath the southern periphery of a Ridge located to the north and west. This ridge is expected to break down and will be replaced by zonal flow Friday into the weekend.
The marine layer this morning was around 2500 ft. This is expected to increase in height some tomorrow morning due to slight increase in onshore flow and a decrease 500 mb heights. This is expected to result in better coverage of marine layer stratus across the Santa Clarita Valley. Patchy morning drizzle will be possible especially near foothills due to orographic lifting. It should be similar on Friday. Classic June gloom. Strong onshore flow will bring slow clearing to the area and no clearing possible for some beaches such as the Ventura coastline.
Temperatures will continue to cool into Friday and remain similar through the weekend (some interior areas could warm slightly on Sunday). Regardless, temperatures will be at or slightly below normal across the csts/vlys and below normal across the interior. The antelope valley will see the smallest change due to lack of marine layer and downsloping winds.
Gusty SW winds especially during the afternoon/evening hours are expected across the Antelope Valley/foothills. Expecting to remain below advisory levels. It will be close on Thursday & Friday with 30-40% chance of an advisory.
(Sun-Wed), 17/216 PM.
Good consensus across deterministic and ensemble suites among global models that an anomalous ridge will begin building across southwest California on Monday. This ridge is expected to peak in strength mid-week with the most reliable guidance showing 597 dm.
This change in pattern will also result in significant reduction in onshore flow. It will also result in shrinking of the marine layer and will limit the valley penetration. However, the increase in heights will strengthen the inversion which could make coastal clearing a little more stubborn (esp. immediate coastline and more confidence early in the week).
(PLEASE READ IMPORTANT)
If current trends continue, a EXTREME HEAT WATCH will likely be needed for Mid-week to highlight a significant heat risk across the area. This product will likely be issued by tomorrow morning (Thursday). It is important that travelers and locals are weather aware and ready during this time. Heat impacts will not be limited just to sensitive populations during this timeframe (such as heat exhaustion and stroke).
There is potential for triple digit heat across the warmest valleys and downtown LA could possibly reach 90F. Due to the onshore flow component, immediate coastal sections will remain cooler with less concern for heat impacts. Heat impacts are likely to linger in some fashion into the weekend, but confidence is lower on the magnitude & details.
17/2354z.
At 23Z at KLAX, the marine layer was 1800 ft deep. The top of the inversion was near 4800 ft with a temperature of 21 Celsius.
High confidence in KPMD & KWJF staying VFR with gusty southwest winds.
High confidence in ceilings at all other airports. Moderate confidence in timing (+/- 3 hours) and flight categories (+/- 500 feet ceilings).
KLAX, High confidence in IFR/MVFR ceilings for the majority of the night and morning. Moderate confidence in timing (+/- 3 hours). No significant east wind component expected.
KBUR, Moderate confidence in IFR ceilings forming tonight with slightly stronger than usual onshore winds in the afternoon and evening hours.
16/852 PM.
Moderate to high confidence in current forecast. Conditions are generally expected to remain below Small Craft Advisory (SCA) levels across most of coastal waters through the forecast period.
Wednesday, local gusts could reach 21 kts (30-40% chance) during the afternoon and evening timeframe for the waters south of Point Conception, especially for western portions of the Santa Barbara Channel and southward to San Miguel Island. Breezy conditions will be ongoing for the waters south of Point Conception each afternoon/evening through Friday, with another chance for SCA gusts Friday afternoon. Lower confidence from Saturday onward, with a chance for widespread SCA conditions Sunday night.
17/233 PM.
A long period southerly swell (14 seconds and 17 seconds) will continue to affect the coastal waters through at least Friday. A Beach Hazard Statement is in effect through Thursday evening due to elevated surf of 3 to 6 feet on south-facing beaches of Ventura County Beaches, Malibu Coast, and Los Angeles County Beaches. Portions of the Southern Santa Barbara County Beaches could see surf to 2 to 4 feet.
Tides of 6.6 to 6.8 feet are predicted to peak around 10 PM to 2 AM tonight (Wednesday Night), and will reach 6.0 to 6.2 feet around the same time Thursday night. The combination of the unusually high tides with elevated surf could result in minor to locally moderate coastal flooding along south exposed coasts, especially near Malibu and Long Beach. In addition, there is along potential for sneaker waves. Stay tuned for updates and refer to CFWLOX for additional details.
Ca, Beach Hazards Statement in effect through late Thursday night for zones 349-350-354-362-366. (See LAXCFWLOX). PZ, NONE.
