13/127 PM.
Seasonal June conditions will continue through the next week as at least weak to moderate onshore flow continues, with night through morning low clouds and fog across most coastal areas. Near to slightly above normal temperatures will continue through early next week, with minor afternoon heat impacts, before cooling down during the middle of the week.
(tdy-Tue), 13/100 PM.
Midday temperatures were running 2-5 degrees cooler across most areas compared to the same time yesterday, with the exception of western Santa Barbara County which was a few degrees warmer, likely related to the quick retreat of the marine layer clouds this morning. Overall, temperatures this afternoon are forecast to be 1-3 degrees cooler than yesterday's highs, under sunny skies. The temperatures will translate to at least minor heat impacts in the afternoon with highs reaching the 80s to near 100 degrees in coastal valleys to interior deserts. For some of the coastal valley and basin areas the added element of humidity (RH>55%) may make temperatures a touch more uncomfortable.
Beyond today, relatively small day-to-day changes are expected Sunday - Monday. With little change in the synoptic flow aloft, surface pressure gradients and subtle marine layer changes will most strongly influence our weather through Monday. In general night to morning low clouds and patchy dense fog (focused across western San Luis Obispo and Santa Barbara Counties) will continue through the period. Breezy afternoon to evening onshore winds across the interior will remain safely below advisory levels. Generally minor heat impacts will continue away from the coast with highs in the 80s to near 100 for coastal valleys to interior.
However, the potential for moderate heat impacts may expand for warmer coastal valleys and the interior early next week as there will be minor warming (2-5 degrees). This is thanks a delayed sea breeze and likely slight shrinking in the marine layer due to to minor offshore trends (actual onshore flow likely to continue even during the typical morning minimum) focused from the north. Model guidance also shows high pressure ridging will strengthen slightly and nudge further into Northern and Central CA, which should lead to minor lower tropospheric warming. Although above normal temperatures will increase heat stress during the day for those interior areas, good cooling trends in the evening and especially overnight should limit overall impacts and therefore the need for heat products. However, those sensitive to the heat may want to consider avoiding peak heat of the day and hydrate often.
Tuesday will likely be similar to Monday if not a degree or two warmer and may be the warmest day through the next week, with above normal temperatures away from the coast.
(Wed-Sat), 13/128 PM.
A slow-developing trough will likely build into region Wednesday or Thursday and bring moderate cooling trends away from the coast, drastically reducing heat risk even to warmer interior areas. Night to morning low clouds will likely continue, but expand well into the coastal valleys and possibly some lower foothills.
The associated onshore push will support gusty onshore to northwest winds nearing advisory levels for the interior, possibly extending to southwest Santa Barbara. There may be a period of enhanced fire weather concern on one or both of those transition days (Wed/Thu) for far interior areas and maybe especially at high elevations, which would be situated above the expanding marine layer influence.
13/1800z.
At 1713Z at KLAX, the marine layer was 1000 ft deep. The top of the inversion was near 2300 ft with a temperature of 21 C.
High confidence in VFR TAFs for KPRB, KPMD, & KWJF.
Moderate confidence in remaining TAFs. Timing of CIG/VSBY restrictions may be off +/- 2 hours and flight minimums by one category.
KLAX, Moderate confidence in TAF. Intermittent CIGs around 010 are possible from 13/18Z-14/00Z as stratus hangs near coastline. Thereafter, IFR CIGs 005-009 should arrive around 14/01Z. CIGs should lift mid-morning tomorrow (MVFR 010), with low confidence if clearing occurs or intermittent CIGs remain thru end of fcst period. No significant east wind component expected.
KBUR, Moderate confidence in TAF. High confidence in VFR conditions through 14/06Z. 30-40% chance of LIFR CIGs 14/12Z-16Z.
13/735 AM.
Moderate to high confidence in current forecast. Conditions are generally expected to remain below Small Craft Advisory (SCA) levels across the coastal waters through the forecast period.
Local gusts could reach 21 kts during the afternoon and evening timeframe across the western Santa Barbara Channel, Santa Monica Basin, and nearshore Los Angeles Harbor into the San Pedro Channel.
Patchy dense fog with visibility 1 sm or less is possible each night to morning through at least Monday.
13/735 AM.
A couple of long period southerly swells (14 seconds and 18 seconds) will move into the coastal waters on Saturday and continue through early next week. A Beach Hazard Statement is in effect from Saturday morning through Monday evening due to elevated surf of 3 to 6 feet on south-facing beaches of Ventura County Beaches, Malibu Coast, Los Angeles County Beaches, and Southern Santa Barbara County Beaches.
Evening tides of 7.5 to 7.9 ft are predicted from Saturday through Tuesday. The combination of the unusually high tides with elevated surf could result in minor to locally moderate coastal flooding for south exposed coasts, along with potential for sneaker waves. Even as tides lower, another southerly swell arrives which could extend concerns into Wednesday night. Stay tuned for updates and refer to CFWLOX for additional details.
Ca, Beach Hazards Statement in effect through Monday evening for zones 349-350-354-362-366. (See LAXCFWLOX). PZ, NONE.
