Area Forecast Discussion
Issued by NWS Los Angeles, CA

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857 FXUS66 KLOX 260337 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 837 PM PDT Sat May 25 2024 .SYNOPSIS...
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25/836 PM. The May gray pattern will continue through next Saturday. Varying amounts of night and morning low clouds and fog are expected for the coast and valleys during the period. Otherwise mostly clear skies will prevail. Temperatures are forecast to be a few degrees below normal into early next week then warm to near normal to a few degrees above normal for mid to late next week.
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&& .SHORT TERM (SAT-TUE)...
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25/835 PM. At upper levels, a broad northwest flow pattern will transition to more of a zonal flow pattern the next few days, with gradually rising heights across the region. Current satellite imagery showing a chaotic marine layer cloud pattern this evening, ACARS data showing a deep but weak marine inversion across the LA basin this evening, around 3500 feet deep. Expecting low clouds to fill in across most coastal/valley areas tonight into Sunday morning, extending locally into the lower coastal slopes. For Sunday night and Monday night, the marine layer depth is expected to become more shallow due to the rising heights across the region, resulting in less marine layer cloud coverage across the interior. Gusty NW winds are increasing this evening across SW Santa Barbara county and may need a wind advisory tonight if winds become more widespread. In general, expecting wind gusts to mostly be in the 35 to 45 mph range, strongest near Gaviota/Refugio. Also seeing some gusty W-NW winds continue across the Antelope Valley and I-5 corridor, which should mostly stay below advisory levels tonight. However, still seeing some local gusts of 45 mph near Lake Palmdale, so may need wind advisory for the foothills tonight. These same areas are expected to see winds the next few days, but generally expected to be weaker than today. Still on track to see a warming trend Sunday and Monday, with little change into Tuesday. Warming will be most noticeable across the interior, especially the Antelope Valley where highs will climb into the mid 80s on Sunday, then around 90 on Monday and Tuesday. .LONG TERM (WED-SAT)...25/155 PM. Not a whole lot of change can be expected in the extended period. It looks like very weak upper troffiness with H5 heights around 584 dam will prevail Wed and Thu, then slightly stronger upper level troffiness will persist Fri and Sat with H5 heights around 581-582 dam. Good onshore pressure gradients to the N and E will help to keep the marine layer pattern over the forecast area Wed thru Sat. Varying amounts of night and morning low clouds and fog are expected for the coast and vlys, moving farthest inland Fri and Sat as the marine inversion deepens. Otherwise, mostly clear skies can be expected. Just subtle changes in temps can be expected each day, with reading expected to be a few degrees below normal for the coast and some vlys and a few degrees above normal elsewhere over inland areas. Afternoon highs for the inland coast, vlys and lower mtns should be in the 70s to mid 80s, while the Antelope Vly heats up into the upper 80s to lower 90s each day. Seasonably breezy onshore to northwest winds will likely continue each afternoon to evening with interior areas prone to west to northwest winds as well as southwest Santa Barbara County potentially reaching close to Advisory levels at times.
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&& .AVIATION...25/2321Z. At 2215Z at KLAX, the marine layer was 3100 ft deep. The top of the inversion was at 6600 feet with a temperature of 12 C. For 00Z TAF package, high confidence in desert TAFs and low to moderate confidence in coastal/valley TAFs. Lower confidence for coastal/valley sites due to uncertainties in the behavior of the marine layer stratus. Timing of flight category changes could be off by +/- 4 hours and CIGs will range from IFR/MVFR levels north of Point Conception and MVFR levels south of Point Conception. KLAX...Low to moderate confidence in 00Z TAF. Timing of return of MVFR CIGs could be +/- 4 hours of current 06Z forecast. Timing of dissipation of MVFR could be +/- 2 hours of current 18Z forecast. No significant easterly wind component is expected. KBUR...Low to moderate confidence in 00Z TAF. Timing of return of MVFR CIGs could be +/- 3 hours of current 09Z forecast. Timing of dissipation of MVFR could be +/- 2 hours of current 18Z forecast. && .MARINE...
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25/817 PM. Moderate to high confidence in forecast. Across the outer waters, Small Craft Advisory (SCA) level winds are expected to continue through this weekend and much of next week. Winds may drop below advisory levels during the morning and early afternoon hours through Monday. Then Tuesday through Thursday SCA conditions are expected to be fairly constant. There is a 30-40% chance of Gale Force winds Tuesday night through Wednesday night. As for seas, starting Tuesday morning seas will build to SCA levels and becoming steep and choppy through at least Thursday night. Across the nearshore waters along the Central Coast, SCA winds this evening will tonight. Then, there is a 30-40% chance of SCA winds during the afternoon and evening hours Sunday and Monday. Tuesday afternoon through Wednesday, SCA level winds and seas are likely (60-70%), with a 20-30% chance of Gale Force winds. Across the southern inner waters, a SCA continues across the western portion of the SBA channel tonight. There is a 30-40% chance of SCA level winds across the western portion of the Channel each afternoon and evening through Tuesday, followed by a 50% chance on Wednesday. South of the Channel Islands, winds are expected to remain below SCA levels through at least Tuesday.
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&& .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect until 3 AM PDT Sunday for zones 645-650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Monday for zones 670-673-676. (See LAXMWWLOX). && $$ PUBLIC...Gomberg/Sirard AVIATION...RAT MARINE...Gomberg/Schoenfeld SYNOPSIS...Sirard weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox