Area Forecast Discussion
Issued by NWS Los Angeles, CA
Issued by NWS Los Angeles, CA
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288 FXUS66 KLOX 221206 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 506 AM PDT Wed May 22 2024 .SYNOPSIS...22/229 AM. Increasing onshore flow will bring a return of persistent night through morning low clouds and fog to the coasts and valleys. Low clouds will struggle to clear from the beaches during the afternoon. An upper-level trough of low pressure will dig south through Morning drizzle is possible on Thursday and Friday. Better clearing and slightly warmer temperatures are forecast for Sunday and Memorial Day. && .SHORT TERM (TDY-FRI)...22/307 AM. Broad pos tilt troffing will continue over the area for the next three days. Onshore flow will increase as well and a night through morning low cloud pattern will dominate the fcst. The marine layer has lowered to about 1400 ft. Increasing onshore flow has pushed low clouds into the coasts and the Santa Ynez Vly. The low clouds have not made much progress into the VTA and LA Vlys due to the lack of an eddy. Slightly higher hgts will bring a few degrees of warming. Most max temps will end up 3 to 6 degrees blo normal. Slightly sharper troffing and stronger onshore flow will combine to deepen the marine layer. The marine layer may rise fast enough to produce some drizzle esp near the foothills. Low clouds will end up covering all of the csts/vlys and will extnd to the foothills and mtn passes. Clearing will be slower than today and many beaches will likely not clear at all. Max temps will drop 2 to 5 degrees due to the clouds, lower hgts and stronger sea breezes. Max temps will wind up in the 60s across the coasts and in the lower 70s in the vlys. Another little trof moves through early Friday. And again it will bring a deep marine layer and possible drizzle. It will come with more cold air than Thursday`s trof and this will bring a stronger onshore push. Look for even slower clearing as well as more coastal areas not clearing at all. The cold air and strong onshore flow will likely bring advisory level gusts to the western Antelope Vly and foothills. The csts/vlys will cool 2 to 4 degrees but all of the cold air advection will drop the interior temps 5 to 10 degrees. Max temps will end up mostly in the 60s and the interior will only peak in the 70s. These temps are 6 to 12 degrees blo normal. .LONG TERM (SAT-TUE)...22/323 AM. The GFS and ECMWF as well as their respective ensemble means are in good agreement for the weekend into early next week. The trof will slowly give way to weak ridging. Hgts will rise from 572 dam to 584 dam. Onshore flow will persist but will weaken. The night through morning low cloud pattern will continue, but the higher hgts will smoosh the marine layer each day and by Monday the low clouds should mostly be out of the vlys. Each day the low clouds should clear a little faster and more completely. Max temps will rise each day esp Sun and Mon when most areas will see 3 to 6 degrees of warming each day. Memorial Day looks quite nice with max temps from the mid 60s to mid 70s across the csts and 70s and lower 80s in the vlys. Mondays temps will be just below normals and with additional warming Tuesday most areas will be within a a degree or two of normal. && .AVIATION...22/1206Z. At 11Z at KLAX, the marine layer was 1800 ft deep. The top of the inversion was at 4900 feet with a temperature of 16 C. High confidence in KPMD and KWJF TAFs. Moderate confidence in remainder of TAFs. Widespread low clouds in coastal and most coastal valley areas. Conds were mostly low MVFR to IFR, except LIFR to VLIFR on the Central Coast and in the foothills. Skies should clear by mid morning in the valleys and early afternoon on the coastal plain. Expect widespread low clouds in coastal and valley areas tonight, with low MVFR to high IFR conditions, except LIFR to VLIFR conds on portions of the Central Coast and in the foothills. KLAX...Moderate confidence in TAF. There is a 20% chance of cigs slipping into the IFR category thru 17Z. There is a 20% chance that cigs will linger until 21Z. There is a 20% chance that cigs will hold off tonight until 06Z or later. There is a 30% chance of an east wind component of 7-8 kt from 09Z-17Z. KBUR...Moderate confidence in TAF. There is a 20% chance that cigs could linger thru 18Z. There is a 20% chance that cigs tonight will arrive as early as 09Z. && .MARINE...22/356 AM. Moderate confidence in forecast, except low-moderate confidence for the inner waters N of Pt. Sal and in the western SBA Channel. In the outer waters, Small Craft Advisory (SCA) level winds and seas will continue much of the time thru Sun. There may be a lull in the winds during the late night thru morning hours, especially Thu night/Fri morning. For the waters N of Pt. Arguello, there is a 20-30% chance of gale force wind gusts Wed afternoon/eve. In the inner waters N of Pt. Sal, there is a 40% chance of SCA level winds/seas in the afternoon/eve hours today and Thu. SCA level winds are likely in the afternoon/eve hours Fri thru Sun. In the SBA Channel and southern inner water, there is a 30-40% chance of SCA level winds in western portions of the SBA Channel in the afternoon/eve hours today and Thu, a 50% chance in the afternoon/eve hours Fri, and a 70% chance Sat and Sun. Otherwise, SCA conds are not expected. A long period S to SW swell will continue to subside today. The risk of larger than normal breaking waves nearshore and stronger currents at many harbor entrances will decrease later today. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement in effect until 2 PM PDT this afternoon for zones 87-362-366. (See LAXCFWLOX). PZ...Small Craft Advisory in effect until 3 AM PDT Friday for zones 670-673-676. (See LAXMWWLOX). && $$ PUBLIC...Rorke AVIATION...DB MARINE...DB SYNOPSIS...30 weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox