Area Forecast Discussion
Issued by NWS Los Angeles, CA
Issued by NWS Los Angeles, CA
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153 FXUS66 KLOX 251024 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 324 AM PDT Sat May 25 2024 .SYNOPSIS...25/321 AM. A warming trend is expected through early next week, most notably away from the coast in response departing trough. Night to morning low clouds will become less common away from the coast during this time frame. && .SHORT TERM (TDY-MON)...25/323 AM. We have observed patchy drizzle early this morning for portions of eastern LA County, focused in the foothills, and near the Central Coast. We may see this continue at times especially for eastern Los Angeles county through mid morning. A strong eddy indicated by a strong -2.5 mb Santa Barbara to San Diego surface pressure gradient has supported a deep marine layer once again focused across southern areas. However, low clouds were slow to fill in as a low cloud replacement cycle was possibly underway (when low clouds gradually reform at a different height). A warming trend is likely through Monday, especially for elevations above 1500 feet or so as the marine layer and associated low clouds will likely shrink in height and coverage in response to a departing trough and associated increasing weight of the atmosphere. Most coastal areas will only warm 3-6 degrees with highs in the mid 60s to mid 70s by Monday. Elevations above 1000-1500 feet and especially interior areas will see warming of 10-15 degrees with highs in the 80s to near 90. West to northwest flow will continue through Monday with a 30-50 percent chance of advisory level winds each afternoon and evening for areas prone to northwest winds such as southwest Santa Barbara County and western Antelope Valley. .LONG TERM (TUE-FRI)...25/323 AM. We have only moderate confidence in the forecast mid week and beyond as the timing of weak trough/ridge systems becomes out of sync within our guidance. This will have limited impacts at the coast with daytime highs likely within three degrees of forecast with continued mid 60s to mid 70s for daytime highs. Away from the coast, including many coastal valleys, may be 5-8 degrees off of the forecast and could be the difference between highs near 80 or 90-95. Night to morning low clouds will likely prevail for coastal areas, expanding into the valleys and lower coastal mountains at times through this period as a weak trough or two progresses through the region. 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 advisory levels at times. && .AVIATION...24/2307Z. At 2230Z at KLAX, the marine layer was 4500 ft deep. The top of the inversion was at 5600 feet with a temperature of 12 C. For the 00Z TAF package, high confidence in desert TAFs and low to moderate confidence in coastal/valley TAFs. Lower confidence in coastal/valley sites due to uncertainties in the behavior of the marine layer stratus. KLAX...Moderate confidence in 00Z TAF. High confidence in return of MVFR CIGs, but low confidence in timing of return (could be +/- 4 hours of current 05Z forecast). No significant easterly wind component is expected. KBUR...Moderate confidence in 00Z TAF. High confidence in return of MVFR CIGs, but low confidence in timing (could be +/- 3 hours of current 07Z forecast). && .MARINE...25/323 AM. Moderate to high confidence in forecast, with higher confidence in winds relative to seas. Across the outer waters, Small Craft Advisory (SCA) level winds are expected to continue through this weekend and much of next week. Winds may briefly drop below advisory levels during the morning and very early afternoon hours Sunday and Monday, but restrengthen to SCA levels by late afternoon. There is a 30-40% chance of Gale Force winds Tuesday night through Wednesday. 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 will push into the western portion of the waters this afternoon and evening. 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, there is a 70-80% chance of SCA level winds across the the Santa Barbara Channel (strongest in the western portion) through this evening. There is a 30% chance of SCA level winds across the western portion of the Channel each afternoon and evening through Wednesday. South of the Channel Islands, there is a 30% chance of SCA level winds pushing into the western portion of the southern inner waters tonight with choppy SCA seas. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect from 3 PM this afternoon to 3 AM PDT Sunday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Sunday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Monday for zones 670-673-676. (See LAXMWWLOX). && $$ PUBLIC...Munroe AVIATION...RAT MARINE...Lund/Gomberg SYNOPSIS...Munroe weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox