07/723 PM.
Temperatures are expected to cool slightly Friday and into the weekend but remain as much as 5 degrees above normal. The hottest temperatures are expected inland, while a shallow marine layer will keep temperatures closer to normal along the coast. Above normal temperatures are expected to continue through most of next week.
(Thu-Sun), 07/750 PM.
***UPDATE***
Earlier this afternoon, the Canyon Fire broke out near Lake Piru and is currently over 1,000 acres. Southwest flow has pushed smokey overcast conditions into the Antelope Valley. Observations at the Lancaster airport indicate the cloud deck around 5,000 ft. Smoke from both the Gifford Fire and Canyon Fire will likely cause air quality issues for surrounding areas. Will continue to monitor the growth and potential impacts.
Low clouds with patchy dense fog are likely to return to the Santa Maria Valley and the Oxnard plain again tonight. Low clouds will affect the beaches of LA County but will likely struggle to move inland tonight into tomorrow morning. Expecting that patchy dense fog may become more widespread along the coast, will issue a Dense Fog Advisory for these areas.
Currently we have some gusty sub advisory Sundowners. Gaviota is reporting gusts to 33 mph and Refugio at 40 mph. These winds are nearing the peak and are expected to gradually decrease after midnight. There are gusty winds in the Antelope Valley and adjacent foothills averaging 15-25 mph, with isolated gusts into the 30s (ie 36 mph at Lake Palmdale).
Highs today were in the 90s to 100s away from the coast. Some locations reached 105F such as the western San Fernando valley. Coastal areas were in the 70s and 80s south of Point Conception and generally remained in the 60s and 70s along the Central Coast. Highs are expected to decrease 1 to 5 degrees south of Point Conception, and the most cooling will be across SLO county, specifically the Santa Lucia mountains (4 to 8 degrees). The forecast continues to remains on track.
***From Previous Discussion***
Forecast is still on track for a couple degrees of cooling the next couple days as the center of the Pacific high will remain north of 40n and the desert southwest high shifts back east slightly. This will cause a 1-2mb increase in the onshore flow to the east and north which will cause a stronger and earlier arriving sea breeze. Since the heat risk calculation came up short for heat advisories today there is no expectation for advisories Friday through the weekend with the very slight cooling trend in the forecast and highs just 2-5 degrees above normal. Looking for the warmest coastal valleys to top out around 100 and deserts in the lower 100s. Inland coastal area expected to be in the 80s to around 90 for Downtown LA while coastal areas remain in the 70s for the most part. Overnight lows will remain in the 60s at lower elevations but in the hills and lower mountain locations lows will be in the 70s.
(Mon-Thu), 07/211 PM.
No appreciable changes to the weather pattern are expected until at least the end of next week. After the minor cool down this weekend, most of the ensemble solutions are keeping temperatures fairly steady within a few degrees until around Thursday. At that point models are showing a more pronounced upper level trough developing along the West coast which will initiate a significant cooling trend with temperatures eventually dropping to below normal levels and increasing low clouds and fog into the valleys.
08/0006z.
At 2255Z at KLAX, the marine layer was 600 ft deep. The top of the inversion was at 2200 ft with a temperature of 30 C.
High confidence in VFR TAFs at KPRB, KBUR, KVNY, KPMD, and KWJF.
Moderate confidence for remaining TAFs for 00Z Package. Timing of CIG/VSBY restrictions may be off +/- 2 hours and flight minimums could be off by one category. FG 1/2SM or less is likely to return to KSMX, KOXR, KCMA and is possible at KSBP & KSBA. However, there is low confidence in timing of CIGs and if they will return to KSBA (25% chance of no CIGs or intermittent).
High confidence then Low confidence in TAFs for KLAX, KLGB, and KSMO after 06Z. Timing of flight cat changes could be off by +/- 3 hours and off by one category. There is a 30-50% chance for no low clouds, highest chances at KSMO.
KLAX, High confidence in TAF through 06Z, then low confidence after due to uncertainty in arrival of low clouds. There is a 40% chance for no low clouds tonight, but if they arrive, there is a 30% chance for cigs 002-004 and vsbys 1-2SM. No significant east wind component expected.
KBUR, High confidence in 00Z TAF.
07/725 PM.
Small Craft Advisory (SCA) will continue across the entire Outer Waters and Inner Waters along the Central Coast through tonight, and through Friday night south of Point Conception. Winds and seas will then remain relatively benign through Monday morning. Moderate confidence (40%) in conditions increasing to SCA levels Monday afternoon into next week for the waters south of Point Conception.
Local SCA level wind gusts will impact western and southern portions of the Santa Barbara Channel in the afternoon/evening through the weekend, with a 20% chance of SCA level gusts reaching nearshore from the Channel Islands Harbor south to Point Mugu, then chances of winds spreading across the Channel increase Monday into next week. There is a 30% chance for local gusts to 21 kts around Point Dume and through the San Pedro Channel each afternoon and evening into next week. Otherwise, conditions will remain relatively benign across the Southern California Bight.
Dense fog will affect portions of the Coastal Waters in the evening through morning hours through at least Saturday morning.
Ca, NONE. PZ, Small Craft Advisory in effect until 3 AM PDT Friday for zones 645-670. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Saturday for zones 673-676. (See LAXMWWLOX).
