Area Forecast Discussion
Issued by NWS Los Angeles, CA
Issued by NWS Los Angeles, CA
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116 FXUS66 KLOX 081032 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 332 AM PDT Sat Jun 8 2024 .SYNOPSIS...08/326 AM. Daytime highs will cool each day through the weekend, and will be well below normal for most locations. Marine layer clouds will extend very far inland each night and morning, with drizzle possible across coast and valleys into next week. Temperates will warm Monday and Tuesday. && .SHORT TERM (TDY-MON)...08/331 AM. Only slight changes in the weather pattern through Monday. This weekend an upper level trough will drop down over the region, and by Monday is likely to break off into a cutoff low, around 300 NM South of Point Conception. Onshore gradients are expected to be strong each day, but trend slightly downward. Marine layer clouds extending across the coasts, valleys, and into the foothills, will remain standard each evening through morning. Clearing will improve slightly each day as onshore gradients slowly decrease. Upper level heights are likely to fall through the weekend, reaching a minimum (~582dam) on Sunday. Temperatures away from the coasts will be most impacted by the cooling airmass aloft, and will trend downward each day this weekend. Even so, daytime highs will be relatively similar for both today and Sunday. Temperatures will be well below normal (by 5 to 10 degrees) for most locations, except near normal for interior areas/deserts. Expect temperatures in the mid 60s to the low 70s for the coasts, mid to upper 70s for valleys, and upper 80s to low 90s for deserts. Monday heights will begin rising as the low stalls south of the region. Temperatures will warm by 2 to 5 degrees, to within around 5 degrees of normal. Overnight-to-morning drizzle will be possible each day, due to falling upper level heights which will allow the marine layer to expand upward. Measurable rain up to a few hundredths of an inch may be recorded at some gauges esp near foothills. Even with onshore gradients trending downwards, they are still forecasted to be strong (LAX to DAG between 7 and 10). Thus gusty southwesterly winds will continue for the Antelope Valley and foothills. Winds are expect to decrease somewhat each day and widespread advisory level gusts are unlikely. .LONG TERM (TUE-FRI)...08/236 AM. Latest model runs of both the GFS and ECMWF and their respective ensembles continue to agree for the overall synoptic pattern next week. Very minimal changes to the weather pattern in the extended period. Onshore gradients are forecasted to be very strong, thus marine layer clouds will dominate the weather pattern for the coasts and valleys, and gusty southwesterly winds will persist across the interior. Tuesday and Wednesday the aforementioned cutoff low is expected to stall around 400 NM South of Point Conception. Thursday through Friday the low will gradually drift eastward, crossing over Los Angeles (or Orange) County Thursday evening. During the day Thursday, the upper low may disturb the capping inversion above the marine layer, resulting in the scattering out of marine layer clouds regionwide. The more likely scenario however, is that the low will simply continue to lift the marine layer, causing overnight- to- morning drizzle, which will be possible through the entire extended forecast period. Besides drizzle, no precipitation is expected, as the low pressure system lacks significant moisture. However precipitable water has trended slightly upward with the latest model runs, so rain chances will continue to be monitored. The greatest vorticity from the system will pass over the area at night, when the atmosphere is the most stable, hindering any convective potential. Friday onshore gradients may start to trend downward, which indicates the potential for the dominant flow direction at the surface to become more northerly, and closer to offshore, going forward. This would dampen the influence of marine layer clouds and afternoon seabreezes, thus warming temperatures for all areas (including the beaches). At this time, conditions on Friday are still expected to be similar to the rest of the week. Any major change in the weather pattern (and a break from June Gloom), looks to be more probable beyond the forecast period, potentially starting next weekend. && .AVIATION...08/0646Z. At 0515Z at KLAX, the marine layer was 2100 ft deep. The top of the inversion was at 5400 ft with a temperature of 23 degrees C. High confidence in TAFs for KWJF and KPMD. Moderate confidence in coastal and valley TAF sites. Timing of flight category changes could be +/- 2 hours of current forecasts. CIG fcsts may be off by +/-200ft. Brief VFR conditions after 22Z are possible for coastal TAF sites from KSBA southward. KLAX...Moderate confidence in TAF. Timing of flight category changes could be +/- 2 hours of current forecasts. There is a 30 percent chc of SCT conds 23Z-02Z. No significant easterly wind component is expected. KBUR...Moderate confidence in 00Z TAF. There is a 30 percent chc that cigs will not go below OVC006. There is a 20 percent chc of VFR conds arriving at 18Z and a 30 percent chc at 19Z. && .MARINE...08/243 AM. For the Outer Waters, moderate to high confidence in current forecast. High confidence in winds and seas remaining below Small Craft Advisory (SCA) levels today. From this evening through Monday morning, there is a 60% chance of SCA level winds most likely on Sunday and Sunday night. From Monday afternoon through Wednesday, high confidence in winds and seas remaining below SCA levels. SCA level winds may return by Friday. extending across the coasts, valleys, and into the foothills, will For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. Tonight through Saturday, high confidence in winds and seas remaining below SCA levels. On Sunday, there is a 40-50% chance of SCA level winds in the afternoon and evening hours. For Monday through Wednesday, high confidence in winds and seas remaining below SCA levels. For the Inner Waters south of Point Conception, high confidence in current forecast. Today through Wednesday, winds and seas are expected to remain below SCA levels. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...Schoenfeld/Rorke AVIATION...Rorke MARINE...Phillips/ASR SYNOPSIS...RS weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox