Marine Weather and Tide Forecast for Hacienda Heights, CA

.SHORT TERM (TDY-MON)...14/807 AM.

***UPDATE***

Latest satellite and surface observations indicate stratus/fog across the coastal plain and valleys with clear skies elsewhere.
Current sounding data indicates marine inversion ranging in depth from 800 feet north of Point Conception to around 2100 feet across the LAX Basin. No significant winds are currently observed.

Forecast-wise for the immediate short term, rather benign conditions are expected. Current stratus/fog should dissipate across many areas by the afternoon, but could linger along the Ventura/LA beaches. Otherwise, mostly sunny skies will prevail through the day. Morning TEMP STUDY data indicates most areas should be a couple degrees warmer today with weaker onshore pressure gradients, bit more shallow inversion and slightly warmer boundary layer. As for winds, typical gusty onshore winds will develop across interior sections with LAX-DAG gradients topping out around 7.5 mb. However, the northerly gradients (SBA-SMX) look to increase this afternoon/evening, so some gusty Sundowners will develop.

Forecast-wise, the current forecast looks to have good handle on the immediate short term. So, no significant updates are expected.
For the afternoon forecast suite, main issue will be the expected strength of the Sundowners both tonight and for the next couple of nights.

***From Previous Discussion***

The marine layer is drastically reduced north of Pt Conception with all of the waters clear and the only low clouds confined to western SBA county. South of Pt Conception a 1400 ft marine layer and onshore flow have brought low clouds to the csts and most of the vlys. The offshore trends should bring faster and more complete clearing today. The faster clearing marine layer, offshore trends and slightly higher hgts will result in 2 to 4 degrees of warming for areas south of Pt Conception while areas north will see little change.

Breezy Sundowner winds will ramp up tonight and will come close to advisory levels across the western SBA county south coast. These winds will keep the south coast cloud free as well. Elsewhere there will be less low clouds, esp in the vlys, as building high pressure smooshes the marine layer to under 1000 ft and the offshore trends continue.

Sunday will be the warmest day as well as the sunniest. Hgts peak near 591 dam and the onshore push to the east will be the weakest.
Actual offshore flow will develop from the north. Most areas will warm 3 to 6 degrees. The big exception will be the SBA south coast where better N to S offshore flow will bring downslope warming and a 12 to 15 degree bump up in temps. The lesser exception will be the Central Coast where temps will not change much. Highs across the Antelope Vly will range from 101 to 103 degrees while the vlys will come in with readings in the 90s. These temps will be close to advisory levels but just under.

Sundowner winds will peak Sunday night. Gusts of 35 to 55 mph will be common from Gaviota to the San Marcos Pass. Isolated gusts near 60 mph are possible near Gaviota/Refugio. Wind advisories are almost a certainty during this time.

A little trof will ripple through the state on Monday. It will lower hgts and increase the onshore flow. There will be a little more low clouds in the morning. Max temps will dip 1 to 3 degrees, but most areas will remain 4 to 8 degrees above normal.

.LONG TERM (TUE-FRI)...14/320 AM.

More cooling on tap for Tuesday, esp for the SBA south coast where the northerly offshore flow will shut off. Most max temps, with the exception of the Central Coast, will remain above normal.

A little ridge will bring warming to most of the area Wednesday except for the LA/VTA vlys where a stronger sea breeze will bring a few degrees of cooling.

Troffing is on tap for next Thu and Fri. Onshore flow to the east will also ramp up to between 8 and 9 mb. Look for a return of the marine layer stratus to the csts and vlys. Clearing will be slow with many beaches likely remaining cloudy all day. Max temps will fall each day and many areas will see below normal max temps. The Antelope Vly will remain above normal however due to down sloping westerly winds. The strong onshore flow will also bring gusty winds to the mtns and the western Antelope Vly.

AVIATION
14/1823Z.

At 1537Z at KLAX, the marine inversion was based at 2100 feet.
The top of the inversion was 5400 feet with a temperature of 21 C.

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

Low confidence in TAFs for KSBP and KSMX. There is a 40% and 20% chance VFR conds prevail, respectively. Otherwise, there is a 30% chance for VLIFR conds. Arrival time of cigs may be off by 2 hours.

Low confidence in TAFs for KBUR and KVNY. There is a 40% chance for LIFR conds at KBUR and KVNY tonight. Arrival time of cigs may be off by 2 hours.

Moderate confidence in remaining TAFs. Clearing of cigs this morning may be off by 90 minutes. There is a 20% chance for VFR conds to prevail at KSBA after cigs clear this morning. There is a 10% chance for VLIFR conds at KOXR and KCMA tonight. Flight cat changes tonight may be off by 2 hours.

KLAX...Moderate confidence in TAF. Return of low clouds could be as early as 04Z or as late as 08Z. There is a 20% for cigs of OVC007-009 upon arrival tonight. No significant east wind component is expected.

KBUR...Low confidence in TAF. There is a 40% chance for OVC002-004 cigs and vsbys 1-2SM. Arrival of cigs could be off 2 hours.

MARINE
14/758 AM.

For the Outer Waters, moderate to high confidence in current forecast. Through Wednesday, high confidence in Small Craft Advisory (SCA) level winds with seas hovering near SCA levels. On Monday and Tuesday, there is a 40-60% chance of widespread Gale force winds.

For the Inner Waters north of Point Sal, moderate confidence in current forecast. Through Wednesday, SCA level winds are expected, mainly during the the afternoon and evening hours, with lighter winds during each late night to morning period. There is a 30% chance of Gale force winds Monday and Monday night.

For the Inner Waters south of Point Conception, moderate confidence in current forecast. High confidence in winds and seas remaining below SCA levels for a majority of the southern Inner Waters through Wednesday, except for the western half of the Santa Barbara Channel where there will be an increasing chance of SCA level winds through the period during the afternoon and evening hours. For Sunday afternoon through Wednesday, there is a 60-80% chance of SCA level winds across the western half of the Santa Barbara Channel (with a 30% chance of Gale force winds Monday and Monday night), but winds are generally expected to remain below SCA levels elsewhere across the southern Inner Waters.

BEACHES
14/321 AM.

A long period south swell will bring elevated surf conditions up to 5-6 feet along south-facing portions of the LA/VTA coastline through the weekend. There will be a high risk for hazardous rip currents - thus be sure to swim near an occupied lifeguard tower.

LOX WATCHES/WARNINGS/ADVISORIES
CA...Beach Hazards Statement in effect through late Sunday night for zones 354-362-366-367. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Sunday for zone 645. (See LAXMWWLOX).
Small Craft Advisory in effect from 3 PM this afternoon to 3 AM PDT Sunday for zone 650. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 AM PDT Monday for zones 670-673-676. (See LAXMWWLOX).