841 FXUS66 KLOX 042357 AFDLOX Area Forecast Discussion...UPDATED National Weather Service Los Angeles/Oxnard CA 457 PM PDT Wed Jun 4 2025 .SYNOPSIS...04/203 AM. Broad troughing and strong onshore flow will bring night through morning low clouds and fog and cooler than normal temperatures through the end of the week. A warming trend will develop for the weekend especially away from the beaches. && .SHORT TERM (TDY-SAT)...04/215 PM. Overall, 12Z models in good synoptic agreement through the short term period. At upper levels, trough will linger over the area through Friday then will become a cutoff low that develops west of Point Conception. Near the surface, moderate to strong onshore flow will continue. Forecast-wise, two main issues in the short term will be convection and the marine layer stratus. With respect to convection, still looks good (as mentioned in the morning discussion) for a slight chance of showers/thunderstorms over the eastern San Gabriel Mountains and adjacent desert foothills this afternoon. For Thursday, instability parameters (CAPE, K-Indices, etc.) decrease a bit over the eastern San Gabriel Mountains, but increase a bit over the Ventura county mountains. Additionally, PWATs increase over the northern Ventura county mountains and remain similar to today over the eastern San Gabriel Mountains. So, still think there is enough moisture and instability to warrant inclusion of a slight chance of showers/thunderstorms Thursday afternoon over the eastern San Gabriel Mountains and the northern Ventura county mountains. Any storms that develop will likely be a mix of wet and dry. So, both brief heavy rain and dry lightning strikes will be possible. The second issue, marine layer stratus, H5 heights remain virtually unchanged tonight. So, with continued onshore gradients, inversion will be deep enough for stratus to push into the coastal slopes tonight. Clearing should be better on Thursday afternoon. For Thursday night through Saturday, rising H5 heights will increase, resulting in more shallow inversion and lesser areal extent of stratus/fog. As for winds, the onshore gradients will generate the usual gusty southwesterly winds across interior sections through Saturday. However, outside of Lake Palmdale, expect winds to remain below advisory levels. Finally with respect to temperatures, will expect a gradual increase in temperatures from day-to-day with lessening marine influence and rising H5 heights. .LONG TERM (SUN-WED)...04/215 PM. For the extended period, 12Z models are not in the best synoptic agreement. The ECMWF and its ensembles indicate more upper level ridging than the GFS family. However, near the surface, both models indicate a continued onshore flow. Forecast-wise, the differences between the models are not expected to produce any significant issues. Through the period, dry conditions are expected. As for clouds, marine layer stratus/fog should remain mostly confined to the coastal plain, before making a bit further inland Tuesday/Wednesday as H5 heights decrease a bit. Other than the marine layer stratus, skies are expected to remain mostly clear through the period. Temperatures will follow the same trend, with a warming trend Sunday/Monday then some slight cooling Tuesday and Wednesday. As for winds, will expect continued onshore breezes each afternoon, but nothing worrisome. && .AVIATION...04/2353Z. At 2305Z at KLAX, the marine layer was 1600 feet deep. The top of the inversion was at 4400 feet with a temperature of 19 C. High confidence in VFR TAFs for KPMD and KWJF. Moderate confidence in all remaining TAFs. There is a 20% chance of IFR/MVFR cigs materializing at KPRB from 08Z to 16Z Thu. There is a 20% chance of intermittent LIFR cigs at KSMX and KSBP from 08Z to 16Z Thu. There is around a 30% chance of no clearing for coastal terminals south of Point Conception through the fcst pd. KLAX...Moderate confidence in 00Z TAF. Arrival and departure of MVFR (010-015) cigs could be off +/- 2 hours. Intermittent IFR cigs (007-009) possible to likely from 08Z to 18Z Thu. Cigs likely to return by 03Z Fri, with a 25% chance of no clearing through fcst pd. No significant east wind component expected. KBUR...Moderate confidence in 00Z TAF. Arrival and departure of cigs may be off +/- 2 hours, with a 30% chance of LIFR cigs from 08Z to 16Z Thu. && .MARINE...04/206 PM. High confidence in unseasonably quiet conditions through Friday with no Small Craft Advisories (SCA) needed. The thunderstorm risk is zero today. More seasonally typical northwest to west winds will form by Saturday or Sunday, with high confidence SCA winds and seas over the Central Coast to San Nicolas Island waters. This will bring short period choppy seas to the nearshore waters as well. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...Thompson AVIATION...Black MARINE...Kittell/Lewis SYNOPSIS...30 weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox