FXUS66 KLOX 192103 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 203 PM PDT Fri Jul 19 2024 .SYNOPSIS...19/105 PM. Well above normal temperatures are expected through early next week, especially the interior areas, though some cooling is expected closer to the coast as onshore flow increases. Night and morning low clouds and areas of dense fog will continue near the coast. && .SHORT TERM (TDY-MON)...19/143 PM. After a cooler start this morning courtesy of dryer air over the area, temperatures have rebounded quite well with most coast/valley areas up 3-6 degrees from yesterday and some of the lower mountain areas up 12 from yesterday. Strong high pressure across the western states is still generating well above normal temperatures across the region, but especially across the far interior where highs approaching 110 are possible each day through the middle of next week. However, closer to the coast and including the some of the valleys a 1200' marine layer and roughly a 3mb onshore flow is providing a moderating effect on the temperatures, keeping highs mostly in the 80s and 90s, except some very low 100s across the western San Fernando Valley, Santa Clarita Valley, and in the southern Salinas Valley. In addition, there have been ample overnight recoveries in those areas with lows mostly in the 60s and even some high 50s. So heat risk in those areas, especially factoring in the relatively cool overnight temperatures, while not zero, are not quite reaching criteria for advisories and warnings. Some of the higher elevations above the valleys, such as the Santa Monica Mountains above 2000 feet, where overnight lows haven't dropped much below 80, heat risk factors are much higher and advisories continue through at least Sunday. Minimal, if any, changes are expected in this pattern through early next week. There will be slight warming across the far interior, but closer to the coast very little change. A shallow marine layer will keep a chance of low visibilities near the coast during the night and morning hours. .LONG TERM (TUE-FRI)...19/156 PM. No significant changes in temperatures early next week so it will remain dangerously hot across the far interior, and 4-8 degrees normal elsewhere. Ensemble based guidance indicates slight warming may develop Tuesday and Wednesday away from the immediate coast which may push some areas into heat advisory territory, particularly across the southern Salinas Valley and warmer parts of the LA/Ventura Valleys. Then as high pressure begins to weaken Thursday and Friday highs in all areas are expected to cool with those trends continuing into next weekend. Lastly, increasing moisture from the southeast east next Tuesday and Wednesday may be enough to bring some thunderstorms back to at least eastern LA County. Otherwise, thunderstorm chances will be under 10% through the period. && .AVIATION...19/1553Z. At 15Z over KLAX, the marine layer was 1200 feet deep. The top of the inversion was at 4000 feet with a temperature of 28 Celsius. High confidence in VFR and minimal concerns through Saturday for KPRB KBUR KVNY KWJF KPMD. All other sites, moderate confidence in any ceilings and visibility being low (LIFR/IFR), low confidence on timing (+/- 6 hours). There is a 30 percent chance in less than 3 hours of VFR conditions today at KOXR. KLAX...Moderate confidence of improvement to VFR occurring as early as 17Z and as late as 19Z. Low clouds could hug the beaches for most of the day, which would result in 5-8SM HZ at the airport lingering into the afternoon. Ceilings will return as early as 00Z and as late as 08Z (low confidence on timing). Moderate confidence in IFR conditions most common, with brief LIFR. High confidence in any east winds staying under 6 knots. KBUR...High confidence in VFR conditions through Saturday with seasonal winds. && .MARINE...19/853 AM. Moderate confidence in dense fog and visibilities under one mile being an issue today and likely through early next week, especially north of Point Mugu and the Channel Islands. The reduced visibilities will likely linger well into the afternoon hours. High confidence in northwest winds increasing each day through Saturday or Sunday. High confidence in at least Small Craft Advisory (SCA) winds and steep seas for the outer waters (offshore from the Central Coast to San Nicolas Island) by this afternoon and lasting through Sunday or Monday night. 70 percent chance of reaching Gales Saturday evening through Sunday evening. Will likely be converting the Gale Watches to Warnings with the afternoon update. For the nearshore Central Coast waters, there is a 10 percent chance of SCA conditions this afternoon and evening, increasing to a 60 percent chance for Saturday and Sunday. Decided to delay the Small Craft Advisory start from this afternoon to Saturday afternoon as a result. For the Santa Barbara Channel, fairly high confidence that SCA winds and seas will stay very localized to the far western portions today and tonight. The winds and steep seas will expand Saturday and Sunday, with a 40 percent chance of those conditions being widespread enough to warrant a Small Craft Advisory. Decided to delay the Small Craft Advisory start from this afternoon to Saturday afternoon as a result. For the rest of the nearshore waters, choppy seas will be building due to the gusty winds in the region, but SCA conditions are unlikely. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Excessive Heat Warning remains in effect until 10 PM PDT Wednesday for zones 38-344-345-353-376>383. (See LAXNPWLOX). Heat Advisory now in effect until 10 PM PDT Sunday for zones 342-343-369-370-375. (See LAXNPWLOX). PZ...Small Craft Advisory in effect from 2 PM Saturday to 3 AM PDT Sunday for zones 645-650. (See LAXMWWLOX). Small Craft Advisory in effect until 2 PM PDT Saturday for zones 670-673-676. (See LAXMWWLOX). Gale Watch in effect from Saturday afternoon through Sunday evening for zones 670-673-676. (See LAXMWWLOX). && $$ PUBLIC...MW AVIATION...Kittell MARINE...Kittell SYNOPSIS...MW weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox