Area Forecast Discussion
Issued by NWS Los Angeles, CA
Issued by NWS Los Angeles, CA
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462 FXUS66 KLOX 012110 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 210 PM PDT Sat Jun 1 2024 .SYNOPSIS...01/128 PM. A persistent marine layer with cooler than normal weather will remain in place through the weekend as strong onshore flow continues across the area. High pressure aloft will build in next week, weaken onshore flow, and bring a warming trend to area. The hottest temperatures are expected for the interior portions of the area Tuesday through Thursday. && .SHORT TERM (TDY-TUE)...01/203 PM. Southwest California continues to be mired in a deep marine layer and strong onshore flow pattern as a result of persistent troughing along the West Coast. While not atypical to have low clouds in May and June, this year does seem to be a little more gloomy than usual. The trough is expected to start loosening its grip Sunday into next week that will bring about a warming trend, especially by Tuesday, with the main focus being the deserts and other areas far removed from the still chilly influence of the Pacific Ocean. There are already signs of improving conditions as northerly flow is starting to develop across our western areas, where satellite imagery is showing low clouds rapidly pulling away from the coast near Pt Conception. In addition, downslope warming due to the gusty north winds passing over the western Transverse range is causing warming and drying conditions there this afternoon. While clearing may not reach all areas to the east and south, this is a good sign that better clearing is likely over the next couple days along with a slight warming trend. Despite these current trends, clouds are expected to reform in most coast/valley areas overnight tonight and last through early afternoon Sunday, and likely longer at some beaches. High pressure tries to build over the area Monday, however, there is one more weak trough that will pass through the West Coast, keeping temperatures on the cooler side still. By Tuesday the trough will be east of California. With weakening onshore flow and a warmer air mass in place most areas should experience a warming trend and much earlier clearing of the marine layer. The one exception will likely be the immediate coast where onshore flow and a strengthening inversion may keep low clouds lingering into the afternoon. Coastal valley highs Tuesday should be close to 90 and even farther inland in the deserts temps should be close to 100. .LONG TERM (WED-SAT)...01/209 PM. The warmest day of this stretch will be Wednesday in most areas as high pressure is at it`s peak locally and onshore gradients are weakest. Still, due to the cold ocean SST`s and likely a strong and low marine inversion, coastal areas temps will only rise to around normal for this time of year. Inland temperatures, though, will climb into the lower 90s for coast valleys and lower 100s for the deserts. A cooling trend will begin in most areas Thursday as high pressure shifts east and onshore flow strengthens. By next Friday and especially Saturday highs will again be 2-5 degrees below normal for coast/valleys with a very likely return of a deepening marine layer that will keep skies cloudy into the afternoon. && .AVIATION...01/1759Z. At 1715Z at KLAX, the marine layer was 2600 ft deep. The top of the inversion was at 4300 feet with a temperature of 20 deg C. Moderate to hi confidence in the 18Z TAFs. Low clouds with IFR/MVFR cigs over the coast and adjacent vlys will clear to near the coast by early this afternoon, except MVFR conds are likely to persist thru the afternoon at KOXR and KLAX and possibly KSMO. IFR/MVFR cigs will likely spread back inland tonight and affect all coast and adjacent vly airfields including KPRB and continue into late Sun morning. The timing of the dissipation and onset of low clouds may be off +/- an hour or two, with the largest uncertainty of the onset of low clouds tonight for KBUR, KVNY and KSBA. For KWJF and KPMD, there is hi confidence VFR conds will continue thru the TAF period. Gusty SW winds will affect these airfields for most of the fcst period. KLAX...Moderate to hi confidence in the 18Z TAF. MVFR cigs will likely persist this afternoon with only a 20% chance of the low clouds scattering out. MVFR cigs will continue tonight thru Sun afternoon. There is a 20% chance of an east wind of 7-8 kt 10Z-16Z Sun. KBUR...Moderate confidence in the 18Z TAF. MVFR cigs are expected until about 20Z then VFR conds will prevail into this evening. IFR cigs should move back in by 07Z this evening before improving to MVFR by 17Z Sun. The timing of the dissipation and onset of the low clouds and changes in flight cats may be off +/- an hour or two. && .MARINE...01/107 PM. In the northern outer waters zone (PZZ670), SCA winds will likely to increase to Gale Force (70% chance) this afternoon and continue thru late tonight. Then, SCA conds are expected (80% chance) late tonight thru Tue. There is a 40% chance gales Sun afternoon/eve. There is a 50% chance of SCA conds Tue night/Wed morning. Conds should then be below SCA levels Wed afternoon through Thu. In the southern two outer waters zones, (PZZ673/676), SCA conds are likely this afternoon (70-80% chance), continuing thru late Mon night or Tue. Conds should then be below SCA levels late Tue night through Thu. In the inner waters N of Pt. Sal, SCA level winds are likely (70% chance) during the afternoon/eve hours today thru Mon and possible thru Tue. Conds will then be below SCA levels Tue night through Thu. In the inner waters S of Pt. Sal, there is a 60% chance of SCA winds in western portion of the SBA Channel during the afternoon and evening hours today through Mon. Otherwise, conds over the inner waters should be below SCA levels thru Thu. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Wind Advisory in effect until 3 AM PDT Sunday for zones 349-351. (See LAXNPWLOX). Wind Advisory in effect until 9 PM PDT this evening for zones 381-383. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for zones 645-673-676. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Sunday for zone 650. (See LAXMWWLOX). Gale Warning in effect until 3 AM PDT Sunday for zone 670. (See LAXMWWLOX). && $$ PUBLIC...MW AVIATION...Sirard MARINE...Sirard SYNOPSIS...Hall weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox