FXUS66 KLOX 191710 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 1010 AM PDT Fri Jul 19 2024 .SYNOPSIS...19/936 AM. Warm temperatures are expected through early next week, especially the far 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-SUN)...19/1008 AM. ***UPDATE*** A few changes to the forecast this morning, namely to cancel the Excessive heat warnings and advisories at lower elevations as the marine layer has refused to budge and remains at around 1200'. This is creating a significant moderating effect for the coastal valleys and highs there, while warmer than yesterday, should only top out in the 90s to lower 100s. Still 4-8 degrees above normal but not really worthy of any heat hazards. Higher up in elevation above the marine layer, including the Santa Monicas, and farther inland across the interior temperatures are still quite hot and a mix of heat advisories and warnings are still in effect. Some additional warming is expected across Antelope Valley, though chances for reaching 110 are under 10% at least through early next week. ***From Previous Discussion*** As for winds, the Western Santa Ynez Range and Southwestern Santa Barbara Coast will see gusty NW Sundowner winds each evening through Sunday night. Tonight and Sunday evening look fairly similar with the SBA to SMX pressure gradient sitting around -2 mb, which will bring gusts of 40 mph to locally 45 mph both evenings. On Saturday evening, the pressure gradient is forecast to strengthen to around -3.3 mb, which could cause a slight increase in the gusts and result in a wind advisory being needed for that evening and night. On Saturday, southerly flow from the low pressure system and the ridge will lead to an increase in southwesterly winds across interior mountains and valleys each afternoon and evening Saturday and Sunday, however will likely remain below advisory levels. .LONG TERM (MON-THU)...19/417 AM. The long-duration dangerously hot conditions will continue through at least Wednesday, at least for the interior mountains and far interior areas. Temperatures will remain fairly similar day-to-day Monday through Wednesday as not much will change synoptically. Nights will remain very warm across the far interior, with forecast lows to be in the 70s to 80s, resulting in little overnight relief and potentially worsen heat impacts. On Thursday, a trough should drop down the west coast and temperatures should drop for the later portion of the week. The potential for daily monsoonal thunderstorms and locally heavy showers continues into mid-week. PWATs will rise to around 1 to 1.5 inches across the region, thanks to the southerly flow funneling the moisture northward. While the moisture continues to increase and expand across the area, confidence remains low this far out so thunderstorms remain out of the official forecast. However, a slight chance of showers nudged into the eastern Antelope Valley and eastern foothills, as well as the eastern San Gabriel Mountains for Tuesday and Wednesday morning. If thunderstorms were to form, they will likely form over the higher terrain and interior valleys of Los Angeles and Ventura Counties and possibly extend into Santa Barbara County by early next week. && .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 remains in effect until 10 AM 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...Lund AVIATION...Kittell MARINE...Kittell SYNOPSIS...MW weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox