Marine Weather and Tide Forecast for Santa Maria, CA

.SHORT TERM (TDY-SAT)...22/921 AM.

***UPDATE***

Temperatures are trending cooler most areas except the Central Coast this morning as onshore flow is increasing ahead of the arrival of a weak trough from the west. The marine layer spread up the coast to Santa Barbara and managed to push into the San Gabriel Valley as the inversion deepened to just under 1500 feet.
The VBG sounding still shows the marine layer depth there under 500 feet so it will be another warm day in the foothills and mountains.

Forecast looks on track for additional cooling Friday and into the weekend.

***From Previous Discussion***

An upper-level ridge of high pressure in place the last several days is breaking down. Onshore flow is strengthening as southwest flow aloft continues to increase this morning. An eddy circulation across the southern California bight is pushing low clouds and fog into southern Los Angeles County. Clouds starting to spill over into the western portion of the San Gabriel Valley and are also trying to work their way north into the Ventura County coastal plain.

A cooling trend will get underway today as onshore flow is progged to continue to strengthen through the day. While today and Friday will likely still remain above normal for most areas, cooling will turn more significant Friday and Saturday, bringing the coastal areas back to normal on Friday. A deepening marine layer combined with stronger onshore pressure gradients will lead to more marine air being transported into the coastal and valleys area. AMDAR soundings from KLAX indicate a 700 foot deep marine layer depth, which agrees well with the latest NAM BUFR time height sections. The marine layer depth should deepen to between 900 and 1200 feet deep on Friday morning, which should allow for clouds to filter into the San Fernando Valley. The marine layer should then deepen additionally to between 2000 and 2500 feet deep by Saturday morning.

North of Point Conception, clouds will continue to remain patchy for this morning, but there will likely be better coverage of the night through morning low clouds and fog tonight and Friday, and more solid coverage will occur on Friday night into Saturday. Low clouds could return to the southern Salinas Valley as soon as Friday morning, but the chances are higher for Friday night and into Saturday morning.

KSBA-KSMX pressure gradients will tighten tonight and again Friday night. NAM-WRF solutions indicate the gradient tightening to -3.9 mb at 06Z Friday, but climatological regimes in place this time of year should permit the gradient to likely fall between -4 and -4.5 mb earlier this evening. With some ample low-level wind support, a wind advisory was added for gusty Sundowner winds across the southwestern portion of Santa Barbara County from late this afternoon and tonight. High-resolution multi-model ensemble members indicate a broader expanse of the winds on Friday night, while EPS ensemble members trend wind gust means higher at KSBA.
Another wind advisory may be needed for the same area on Friday night while expanding across the Santa Ynez Range slightly.

.LONG TERM (SUN-WED)...22/436 AM.

The marine layer depth could thin slightly and the low cloud extent could retract some on Sunday. Cluster analysis reveals weak ridging aloft to be favored, but southwest flow should persist and keep onshore flow in place. If there were a day for clouds to struggle to clear from the coast, it could be Sunday as the marine inversion should tighten and inhibit mixing of marine intrusion. Stay tuned as this could be the wrinkle in the forecast.

By Monday, troughing aloft should reestablish and linger through much of next week. While there is some uncertainty on how strong the trough will be, cluster analysis favor troughing for much of the work week. EPS ensemble members keep temperature means closer to climatological averages and a persistent night through morning low cloud field in place.

AVIATION
22/1134Z.

At 0757Z, the marine layer depth was around 700 feet deep at KLAX. The top of the inversion was 2000 feet with a temperature near 24 degrees Celsius.

High confidence in TAFs for KPRB, KPMD, and KWJF.

Low to moderate confidence in remaining TAFs. Low clouds this morning will remain IFR to MVFR as the Catalina Eddy has lifted cigs higher than anticipated. Cigs may go in and out of sites this morning, but all sites should clear by 18Z-20Z. MVFR vsbys may linger into the afternoon at coastal sites due to shallow inversion. Timing of arrival of cigs tonight may be off +/- 3 hours. MVFR cigs are generally expected as the Catalina Eddy reforms tonight and continues to lift cigs. There is a 40% chance for IFR to MVFR conds at KBUR/KVNY late tonight. Periods of light to moderate LLWS and turbulence are possible between 22Z and 06Z at KSBA.

KLAX...Moderate confidence in TAF. There is a 40% chance for cigs 008-010 through 17Z. Clearing time may be as early as 16Z or as late as 18Z. MVFR vsbys may continue through 20Z. Arrival time tonight could be off +/- 3 hours, and there is a 20% chance for cigs 007-010. There is a 15% chance for an east wind component reaching 8 kts after 07Z Friday.

KBUR...Low confidence in TAF. There is a 40% chance for cigs 007-015 and or vsbys 2-5SM after 07Z.

MARINE
22/840 AM.

High confidence in Small Craft Advisory (SCA) level winds and seas continuing through Memorial Day Weekend in the Outer Waters, with a 40-70% chance for GALES through late Friday night. Chances for Gales decrease to 10-20% Saturday through Monday.

For the northern Inner Waters, high confidence in a combination of SCA winds and/or seas through Friday, with highest chances in the afternoon and evenings. There is a 70% chance for Gale force winds this afternoon and evening, and a 40% chance Friday. There is a 60% chance for SCA winds especially during afternoon/eve hours over the weekend.

There is a 60-70% chance for SCA level winds in the western portion of the Santa Barbara Channel this afternoon through late tonight. SCA level winds will be more widespread Friday, including reaching the Ventura County coastline, and there is a 20% chance for Gale Force winds in the western portion of the channel. There is a moderate chance for SCA level winds across the western portion of the channel each afternoon and evening over the remainder of Memorial Day Weekend.

For the Inner Waters off the Los Angeles and Orange County coasts, high confidence in conditions remaining below advisory levels today. There is a 20-40% chance for local gusts to 25 kt to occur Friday through Monday in the afternoons near Malibu and in the western portion of the zone. Highest chances are Friday and Sunday.

Dense fog with reduced visibility is possible at times through this evening.

LOX WATCHES/WARNINGS/ADVISORIES
CA...Wind Advisory in effect from 3 PM this afternoon to 3 AM PDT Friday for zones 349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 PM PDT this afternoon for zones 645-673-676. (See LAXMWWLOX).
Gale Warning in effect from 3 PM this afternoon to 9 PM PDT this evening for zone 645. (See LAXMWWLOX).
Small Craft Advisory in effect from 5 PM this afternoon to 3 AM PDT Friday for zone 650. (See LAXMWWLOX).
Gale Warning in effect until 3 AM PDT Friday for zone 670. (See LAXMWWLOX).
Gale Warning in effect from 3 PM this afternoon to 3 AM PDT Saturday for zones 673-676. (See LAXMWWLOX).