404 FXUS66 KLOX 051803 AFDLOXArea Forecast Discussion...UPDATED National Weather Service Los Angeles/Oxnard CA 1103 AM PDT Fri Sep 5 2025
.SYNOPSIS...05/257 AM.
Temperatures are expected to be within a few degrees of normal today through the weekend. Then next week much cooler weather is expected as a low pressure system approaches California.
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.SHORT TERM (TDY-SUN)...05/914 AM.
***UPDATE***
Pretty quiet morning weather-wise. The marine layer was around 1500 ft deep at KLAX and Vandenberg, with low clouds spreading across the coast, making it into the Eastern San Fernando Valley/San Gabriel Valley, the Santa Ynez Valley, and down into the southern Salinas Valley locations (like Paso Robles). A few stations across the Central Coast reporting 0.01 inches of rain (drizzle) due to the deeper marine layer this morning.
Temperatures today will be somewhat similar to the previous day, with highs across the interior in the mid to high 90s (including the warmest valleys), and high 80s to low 90s away from the coasts, with 70s to locally 80 at the beaches.
Besides some Cumulus cloud build up, mainly over the interior San Luis Obispo and Santa Barbara County Mountains, monsoonal thunderstorms are expected to remain east/south of our four county area (SLO to LA Counties).
Otherwise the forecast looks to be in shape and no updates were needed.
***From Previous Discussion***
Overall a quiet weather pattern this weekend into next week. A weak upper level ridge will remain in place over southern California through the weekend with temperatures near to slightly above normal. Low clouds will continue to form overnight and move over the coastal areas with clearing by afternoon. Some low clouds and fog are also expected in the southern Salinas valley during the morning hours.
Starting Monday a significant cooling trend is expected to begin area-wide as an unusually cold upper level trough forms over West coast. High temperatures will drop to 3-6 degrees below normal with low clouds and fog pushing into the valleys during the night and morning hours and slow cooling across the coastal areas.
.LONG TERM (MON-THU)...05/337 AM.
There is good agreement amongst the ensemble solutions that the cooling trend will continue through at least mid week with highs 6-12 degrees below normal, especially inland where highs in some areas may not even reach 80 degrees. There may even be some drizzle up against the coastal slopes as the marine layer reaches at least 3000 feet.
While a majority of the longer range model solutions show a slow warming trend beginning later next week, some of the more recent solutions are now favoring well below normal temperatures continuing through at least next Friday, and then only a very slow warming trend into the week of the 14th. With a persistent trough pattern along the West coast the next week or more the monsoon conditions will be far to the east with little or no chance of any afternoon thunderstorms.
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.AVIATION...05/1802Z.
At 1716Z at KLAX, the marine layer was 1200 feet deep. The top of the inversion was 3200 feet with a temperature of 26 C.
High confidence in VFR TAFs for desert airfields (KPMD & KWJF).
Overall, moderate confidence for remaining TAFs. Least confident in arrival of CIGs (+/- 3 hours). Departure times likely will be accurate within +/- 2 hours of current forecast. Good confidence in flight categories. There is a 25% chance of no low clouds at KSBA. There is a 10% chance of that IFR CIGs will arrive at KVNY & KBUR.
KLAX...Moderate confidence in 18Z TAF. Arrival and departure times of CIGs may be off by 2 hours. Flight cats could be off by one. No significant east wind component expected.
KBUR...Moderate confidence in 18Z TAF. There is a 10% chance of IFR CIGs from 08Z to 16Z Sat.
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.MARINE...05/808 AM.
High confidence in the current forecast through early Saturday morning, then moderate confidence thereafter. Slightly higher confidence in the sea forecast relative to the wind forecast through Sunday, then higher confidence in winds thereafter.
For the waters southwest through northwest of the Channel Islands and the nearshore waters along the Central Coast, Small Craft Advisory (SCA) level winds will develop by this afternoon and continue through at least this evening. There is a moderate-to- high chance of SCA level winds for Saturday afternoon and evening, then there is a high chance of extended period of SCA conditions early next week. There is a small chance of Gales between Monday and Wednesday during the afternoon and evening hours across the waters south of Point Conception.
Inside the southern California bight, there is a moderate chance of SCA level wind gusts this afternoon and evening across the far western portion of the Santa Barbara Channel and into the Anacapa Passage, near Point Dume, and into the San Pedro Channel. Otherwise, winds and seas will remain below SCA levels through Sunday. There is a moderate to high chance of SCA level winds each afternoon and evening between Sunday and Tuesday across the SBA Channel.
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.LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect until 9 PM PDT this evening for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Saturday for zones 670-673-676. (See LAXMWWLOX).
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PUBLIC...MW/KL AVIATION...Black MARINE...Hall/Black SYNOPSIS...MW
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox
NWS LOX Office Area Forecast Discussion