Marine Weather and Tide Forecast for Marina del Rey, CA

.SHORT TERM (THU-SUN)...19/823 PM.

Clouds are much less entrenched versus this time last night as a northerly surface pressure gradient starts to strengthen this evening. Gusty Sundowner winds are surfacing across southwestern Santa Barbara County this evening with gusts between 35 and 47 mph being observed at this time. KSBA-KSMX surface pressure gradients have tightened to -3.6 mb currently. A wind advisory remains in effect for the southwestern portion of Santa Barbara County through early Saturday morning. The surface pressure gradient is expected to tighten into Friday night and the latest high resolution model solutions are indicating KSBA-KSMX surface pressure gradients leaning to between -5 mb and -6 mb on Friday evening. Given the higher resolution model wind data indicating a broader swath of 40 knot surface winds and NAM-WRF 950 mb thermal gradients approaching 14 degrees Celsius, a high wind watch is being considered for southwestern Santa Barbara County for mainly Friday evening. With a stronger pattern developing, a wind advisory will also likely be needed on Friday night for the southeastern portions of Santa Barbara County, as well.

A wrinkle is starting to develop with the latest higher resolution model solutions trending toward a drier and windier event across the eastern portion of Santa Barbara County on Saturday night. KSBA-KBFL surface pressure gradients approach -4 mb, but when in combination with KSBA-KSMX surface pressure gradient, local studies suggest a greater than 50 percent chance of advisory level winds in the Montecito area. Near critical fire weather conditions could develop on Saturday night across the greater Santa Barbara area. This will need to be monitored closely over the next 24 to 36 hours.

Otherwise, a cooling trend is expected over the coming days with a stronger west to northwest push. Clouds confined to the Los Angeles County this evening should expand back northward and return to the valleys again as an eddy circulation remains. Patchy low clouds in place already along the Central Coast should expand through the night as the air mass cools to the dewpoint. At least, areas of low clouds and fog will develop, but higher confidence exists in the clouds expanding across the Central Coast and into the Santa Ynez Valley.

***From Previous Discussion***

There were a few low clouds along some of the beaches early this afternoon and these may persist until late today. Otherwise, sunny skies prevailed across the region which will continue through sunset. A rapid increase in onshore pressure gradients were noted into the afternoon, with the NAM fcst LAX-DAG gradient topping out around +9.7 mb at 00Z this afternoon, while the LAX- BFL gradient is expected to be +5.7 mb at that time. These onshore gradients will help to bring gusty NW winds to the Central Coast and SW SBA County by mid to late this afternoon, as well as gusty W-NW winds from the I-5 Corridor of NW L.A. County to the Antelope Vly. Gusty NW winds will also affect portions of the Santa Lucia range and Salinas River Vly starting late today or early this evening. Winds gusts are expected to reach Advisory levels for many of these areas and a series of Wind Advisories have been issued. Elsewhere this afternoon into this evening, breezy to gusty SW-NW winds will affect many other areas as well.

Temps this afternoon will be several degrees cooler in all areas compared to the last few days, but remain 4-8 deg above normal for most areas, except dropping to a few deg below normal for the Central Coast into the Santa Ynez Vly. The warmest vlys and lower mtns should top out in the mid 80s to mid 90s, except around 100 for the Antelope vly.

A broad upper level trof will prevail over the region through Sun, altho the lowest H5 heights will be Sat night and early Sun at around 575-579 dam. A broad W to WSW flow aloft will prevail thru the period.

A marine layer pattern for the most part can be expected tonight thru Sun, with varying amounts of night and morning low clouds and fog for the coast and vlys, altho the extent of the low clouds may be a bit less Sat night into Sun morning due to some northerly offshore flow and offshore pressure gradients and trends.

Winds will continue to be factor in the fcst thru Fri night and possible into Sat as strong onshore gradients persist. The strongest winds will likely be Fri night for SW SBA County and into the L.A. county mtns including the I-5 Corridor and portions of the highway 14 corridor. The Wind Advisories are in effect thru late Fri night for many of these areas. Please see the latest Non-Precipitation Weather Message (LAXNPWLOX) for further details.

Temps are forecast to be about 10 degrees cooler on Friday then another 2 to 5 deg cooler on Sat before warming back up several deg on Sun due to the offshore gradients. Highs will be several deg below normal in all areas Fri thru Sun, coolest on Sat at 6-12 deg or more below normal for many inland areas.

.LONG TERM (MON-THU)...19/218 PM.

EC and GFS in generally good agreement during the extended. The upper level trof will linger over srn CA Mon and Tue, then some upper level ridging should move into the area Wed and Thu.

Night and morning marine layer clouds and some fog is expected for much of the coast and vlys each day thru the extended period.
Breezy to gusty SW to NW winds can be expected each afternoon into the evening. Temps should continue to be several deg below seasonal norms Mon and Tue, then warm to slightly below normal on Wed and to near normal to slightly above normal on Thu.

AVIATION
20/0131Z.

Around 00Z, the marine layer depth was around 1600 feet deep at KLAX. The top of the inversion was 2500 feet with a temperature near 22 degrees Celsius.

High confidence in the current forecast for desert terminals.
Moderate to high confidence in the current forecast for coastal and valley terminals. Higher confidence exists in flight categories. Less confidence exists in timing. Timing of arrival could be off by four hours and clearing off by up to two hours.

IFR to MVFR conditions will spread back into most coastal and valley terminals overnight. There is a low chance that flight categories could be one category higher than forecast.

There is a moderate chance of moderate to strong low-level wind shear and turbulence at terminals from KSBA north through 05Z, and after 22Z.

KLAX.. MVFR conditions will continue to spread into KLAX through 09Z. There is a 30 percent chance of IFR conditions between 02Z and 09Z. VFR conditions could develop as soon as 16Z, or as late as 20Z.

KBUR...IFR to MVFR conditions will spread in as early as 06Z, or as late as 10Z. Higher confidence exists in MVFR conditions, but there is a 40 percent chance of IFR conditions from arrival until 15Z. VFR conditions could develop as soon as 16Z, or as late as 18Z.

MARINE
19/820 PM.

***HAZARDOUS SEAS THURSDAY THROUGH SATURDAY***

High confidence in prolonged upper-end Gale Force northwest winds beyond 20 miles from shore tonight through Saturday night.
Moderate confidence in gusts of 30 to 35 knots impacting the nearshore Central Coast waters and western Santa Barbara Channel each afternoon and evening during this stretch. All waters will see building and hazardously steep short period seas. Small craft should stay in safe harbor, especially in the afternoon and evening hours.

High confidence in lowering winds and subsiding seas for the first half of next week, with abnormally large high tides each evening.

LOX WATCHES/WARNINGS/ADVISORIES
CA...Wind Advisory remains in effect until 9 PM PDT Friday for zones 340-341-346-347. (See LAXNPWLOX).
Wind Advisory remains in effect until 3 AM PDT Saturday for zones 342-343-349-351-379-381>383. (See LAXNPWLOX).
High Wind Watch in effect from Friday afternoon through late Friday night for zones 349-351. (See LAXNPWLOX).
Wind Advisory in effect from 4 PM Saturday to 3 AM PDT Sunday for zones 350-352. (See LAXNPWLOX).
Wind Advisory now in effect until 3 AM PDT Saturday for zone 378. (See LAXNPWLOX).
PZ...Gale Warning in effect until 3 AM PDT Friday for zone 645. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 PM PDT Friday for zone 650. (See LAXMWWLOX).
Gale Watch in effect from Friday afternoon through late Friday night for zone 650. (See LAXMWWLOX).
Gale Warning in effect until 3 AM PDT Sunday for zones 670-673-676. (See LAXMWWLOX).