Area Forecast Discussion
Issued by NWS Los Angeles, CA
Issued by NWS Los Angeles, CA
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954 FXUS66 KLOX 180226 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 726 PM PDT Sat Aug 17 2024 .SYNOPSIS...17/206 PM. Aside from night and morning low clouds and fog near the coast at times, quiet weather is expected through next week. A warm-up is expected for Tuesday and Wednesday particularly for the interior. && .SHORT TERM (SAT-TUE)...17/206 PM. Through the remainder of this weekend, dry southwesterly flow will prevail over the local area -- between persistent upper troughing off the Pacific Northwest coast and a midlevel ridge building over the south-central states. Onshore flow will maintain significant coverage of low clouds and perhaps patchy fog over coasts and coastal valleys during the night and morning -- given marine-layer depths over 2000 feet observed at KLAX this afternoon with, initially, little change in midlevel heights. Night and morning low clouds and fog will dissipate by mid-day each day. The onshore flow will keep high temperatures near the coast a few to several degrees below normal near through Monday, with highs over interior areas of a few to several degrees above normal. Modest offshore pressure gradients for SBA-SMX will facilitate sub- advisory Sundowner winds across southern Santa Barbara County each day. Tuesday high temperatures will increase 2-4 degrees areawide in response to the mid-level ridge expanding westward over the local area, which will also correspond to a shallower marine layer and lower-coverage marine stratus and fog especially as synoptic-scale subsidence yields drying trend. Probabilities for heat headlines over interior areas are less than 20%. .LONG TERM (WED-SAT)...17/206 PM. Wednesday high temperatures will still be quite warm away from the coast -- running a few to several degrees above normal over interior areas -- as the strengthened midlevel ridge persists over the region. Light onshore flow will keep temperatures cooler near the coast. Later in the week, the latest medium-range model consensus indicates the aforementioned trough becoming reinforced with heights aloft falling across the local area. Correspondingly, a cooling trend is expected for Thursday and Friday and into next weekend. Despite the lower heights aloft, significant synoptic- scale drying will slow the return of marine stratus and fog over coastal areas -- though low clouds and fog should return to the LA County coast and Central Coast by late next week and then overspread other coastal areas thereafter. The upper-level pattern will be unfavorable for convective development through next week. && .AVIATION...18/0220Z. At 0004Z at KLAX, the marine layer was 1100 ft deep. The top of the inversion was 2500 ft with a temperature of 23 Celsius. High confidence in VFR conditions through at least Sunday at KPMD and KWJF with slightly stronger and more persistent than usual onshore flow. Moderate confidence in lower ceilings tonight. Expecting LIFR/IFR ceilings for KPRB, KSBP and KSMX, and IFR/MVFR ceilings for remaining TAF sites. Low confidence on arrival times. KLAX...Moderate confidence in current TAF. There is a 30% chance of 1-4 hours of BKN008 from 00-05Z. A second round of cigs (OVC008-015) are expected as early as 06Z and as late as 10Z. High confidence that any east wind component will stay under 6 knots. KBUR...High confidence in VFR conditions through at least 04Z. 60% chance of BKN006-10 forming as early as 08Z and as late as 14Z. && .MARINE...17/147 PM. For the outer waters from the Central Coast to San Nicolas Island, moderate confidence in Small Craft Advisory (SCA) level winds for the waters south of Point Sal (Zones PZZ673/676) through Tuesday night, with lulls possible in the morning hours each day. For the furthest northern zone (PZZ670), high confidence winds will be below advisory levels through Sunday morning. Moderate confidence in winds picking up to SCA level Sunday afternoon thru Tuesday night. For the nearshore waters off the Central Coast, high confidence in conditions remaining below SCA levels through Sunday morning. Moderate confidence in SCA level winds occuring during the afternoon thru evening hours tomorrow through early next week. For the Santa Barbara Channel, moderate high in winds remaining below SCA level thru Sunday morning, and moderate confidence thru Monday morning. There is a better chance of SCA level winds in the Western Portion of the Channel Monday and Tuesday afternoon thru evening hours. In the eastern portion, high confidence in conditions remaining below SCA level through early next week. For the southern inner waters, high confidence in conditions staying under SCA levels through the period. With a shallowing marine layer, moderate confidence in patchy dense fog with visibilities under 1 nautical mile effecting the Central Coast waters tonight thru at least Monday morning, especially in the overnight to morning hours. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect until 3 AM PDT Monday for zones 673-676. (See LAXMWWLOX). && $$ PUBLIC...Cohen AVIATION...Phillips MARINE...Lewis/Lund SYNOPSIS...Cohen weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox