Swell Matrix

Area Forecast Discussion

National Weather Service Los Angeles/Oxnard Ca

1001 am PDT Wed Sep 23 2026

Synopsis

23/306 AM.

High temperatures will peak today, with highs 5 to 10 degrees above normal. The marine layer will shrink during this time, with overnight low clouds and fog limited to coastal areas through at least Thursday night.

Short Term

(tdy-Fri), 23/306 AM.

Look for a nice warm up today as a little ridge tries to sneak in from the west and raise hgts to 585 dam. More importantly there will be weak offshore flow form both the E and N in the morning and only weak onshore flow in the afternoon. The offshore flow has pretty much eliminated the marine layer clouds which will be almost all confined to the SBA county west coast. Max temps will respond to the sunshine, increased hgts and morning offshore flow by jumping 5 to 10 locally 12 degrees. The csts will see max temps mostly in the 80s with a few 90 or 91 degree readings. The vlys will be in the upper 80s and 90s. These max temps are 3 to 6 degrees over normal with the exception of the Central Coast which will end up 5 to 10 degrees warmer than normal.

Slight hgt falls brought on by a large trof moving into the PACNW along with onshore trends will bring an increase in morning low clouds across the csts Thursday morning. Max temps will also respond to the these trends and fall 2 to 4 degrees.

Not much change on tap for Friday. Look for SW flow overhead as the state will sit between a large upper high over TX and the big trof over the PACNW. There will be some morning low clouds over the cstl sections but a little offshore push will bring earlier clearing and slight warming to the csts vlys while bring cooler air into the far interior.

Long Term

(Sat-Tue), 23/307 AM.

Look for two days of cooling with an increase in the amount and persistence of the morning marine layer stratus clouds. Most of this is due to the increasing effects of the PACNW trof as it moved into CA and also an increase in onshore flow. The Central Coast will see the biggest cool down (4 to 8 degrees) on Saturday as the trof will affect them the most and the onshore flow will be the strongest. All areas will cool 3 to 6 locally 8 degrees on Sunday as a thick layer of blow off clouds from the two hurricanes move overhead. Max temps across the Central Coast will only be in the 70s on Sunday while south of Pt Conception max temps will end up in the mid 70s to mid 80s. Most of these max temps are about 2 to 4 degrees blo normal.

The trof will exit the areas on Monday. It will not move fast enough to really change the sensible weather south of Pt Concpetion, but the building ridge behind the trof will bring 3 to 6 degrees of warming to the Central Coast. Current mdls show any rain from the moisture assoc with the Hurricanes to fall to the south of LA county but there is a non zero chance that some rain could fall.

A ridge is fcst to move into the area on Tuesday and should bring sunnier skies and 3 to 6 degrees of warming.

The hurricanes will likely bring a large ocean swell to the area with the potential for coastal flooding. Please follow the evolution of this threat by reading the beaches discussion below.

Aviation

23/1659z.

At 1618Z at KLAX, the marine layer was 1100 ft deep. The top of the inversion was at 2600 feet with a temperature of 26 C.

High confidence in VFR TAFs for KPMD, KWJF, KBUR, and KVNY.

Moderate confidence in remaining 18Z TAFs. Timing of CIG/VSBY restrictions may be off +/- 2 hours and flight minimums by one category. There is a 30% chance that no clouds arrive at KSBP.

KLAX, Moderate confidence in TAF. Arrival and clearing times of CIGs 010 (+/- 200 ft) may be off +/- 2 hours. No significant east wind component expected.

KBUR, High confidence in TAF. No wind issues expected.

Marine

23/739 AM.

Small Craft Advisory (SCA) northwest winds will linger longest across the northern outer waters into the evening hours (PZZ670). Conditions will then drop below advisory levels for all waters through Thursday afternoon. SCA level winds are likely to return Thursday evening/night starting across far northern waters and locally near Point Conception. By Friday afternoon or evening, these winds will expand to cover the majority of outer waters and even reaching into the nearshore waters along Central Coast. Short-period steep, choppy seas most likely during this timeframe. Coverage and wind strength is likely to decrease some on Saturday with more focus near Point Conception. These SCA winds will expand in coverage again Sunday through early next week with increasing potential to reach into the Santa Barbara Channel.

Beaches

22/835 PM.

The eastern Pacific is currently active with Hurricane Polo, tropical storm Odalys, and a developing disturbance southeast of Hawaii. This activity will produce southerly swells (SW-SE) which will impact the southern California coastline as early as Friday into the weekend, with better chances early next week. Confidence is currently low on the evolution of these systems, the magnitude, and exactly how the swells will propagate. Stay tuned for future updates as we continue to monitor these storms.

Watches, Warnings, Advisories

Ca, NONE. PZ, Small Craft Advisory in effect until 9 PM PDT this evening for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until noon PDT today for zone 673. (See LAXMWWLOX).

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