Marine Weather and Tide Forecast for Lompoc, CA

.SHORT TERM (SAT-TUE)...07/836 PM.

***UPDATE***

Today was another warm day with daytime highs in the mid 60s to low 80s. Tomorrow temperatures are expected to drop with falling 500 mb heights and the return of onshore flow, with most highs remaining in the 60s up to the low 70s. Additionally, there continues to be a chance of overnight-to-morning dense fog for the coastal waters and the LA County Coast through Monday morning.

Models remain on track for a significant strong Santa Ana Wind event peaking Monday night into Tuesday. The high resolution models will soon cover the event, which will likely further increase forecaster confidence. Overall, the forecast is on track with no major chances with this update.

***From Previous Discussion***

High temperatures are expected to cool 6-12 degrees Sunday and Monday as light onshore flow returns. That still keeps most of the area 3-6 degrees above normal. And along with that shift to light onshore flow there is a 50-70% chance of a shallow marine layer returning to coastal areas with areas of very dense fog. Aside from that Sunday and Monday will be relatively low impact weather days.

The biggest concern in the short term weather is the expected development of another potentially very dangerous Santa Ana wind event Monday night into Tuesday, creating significant fire weather conditions. The NAM has double downed on the gradients with the 12z run, boosting an already impressive gradient of -8mb on the Friday models to a hefty -10mb with the 12z run this morning.
Couple that with 50kt sustained winds as low as 900mb and strong cold advection and the ingredients are in place for a very strong Santa Ana wind event. This event is maximized with an easterly wind component and very little north component, which typically favors the entire Oxnard/Ventura/Camarillo plain and through the interior Ventura County valleys, along with the usual areas of the Santa Clarita Valley as well as the San Gabriels and Santa Susana Mountains. A -10mb gradient would be greater than the 97th percentile of all offshore events over the last 30 years or so.
And often, especially with strong events, the actual gradient will weaken by 1-2 mb. In any case, even an -8mb gradient with similar support aloft will produce very strong winds.

As mentioned, this event has quite a bit of cold air advection with it so this will not be a particularly warm Santa Ana event.
However, temperatures are expected to remain mostly in the 70s which for this time of year is at least 3-6 degrees above normal.
With humidities dropping into the teens and single digits during the day and minimal overnight recovery, areas that are sheltered from the winds at night will see temperatures drop considerably, with areas of frost/freeze likely. The most notable areas would be the Antelope Valley and portions of interior SLO County where overnight temps in the 20s are likely, and the AV could see some high teens.

.LONG TERM (WED-SAT)...07/204 PM.

Some lingering offshore winds expected on Wednesday but with upper support dropping off winds are expected to be much weaker than Tuesday. The rest of the week will feature a gradual return to onshore flow as models continue to advertise another storm system hitting the West Coast either Friday or Saturday. Still quite a bit of ensemble spread, but overall the trend has been towards a weaker system, and decreasing chances for rain south of Santa Barbara. All the 12z ensembles keep rain amounts in the LA area at less than a tenth of an inch (with roughly 50% of the solutions showing no rain), and only around a quarter inch across northern areas.

AVIATION
08/0000Z.

Around 23Z at KLAX, the shallow marine layer was 200ft deep. The top of the inversion was 1700ft with a temperature of 22C.

Overall, moderate confidence in 00z TAF Package. Lowest confidence in coastal TAFs (KSBA and south) from 06z-18z. If cigs arrive, expect VLIFR/LIFR conds. Highest confidence in cigs arriving for KLAX and KLGB. Timing of cigs/vsby restrictions may vary +/- 2 hours. Otherwise, high confidence in light winds and VFR conds elsewhere.

KLAX...There is around a 30 percent chance of VLIFR conditions between 10Z and 17Z. Good confidence in east wind component remaining below 8 knots.

KBUR...VFR conditions are expected thru the pd.

MARINE
07/757 PM.

Moderate confidence in the current forecast. Slightly higher confidence in seas relative to winds.

Small Craft Advisory (SCA) level winds will be most widespread and strongest for western portions of PZZ670/673 (50 NM + from coastline). Borderline SCA level seas likely starting overnight Sunday should stay confined to the aforementioned area, especially in PZZ670. By Monday Afternoon, wind and seas should be below SCA criteria, and should remain through Wednesday.

For the Inner Waters south of Point Conception, specifically nearshore Ventura to Malibu west to the Channel Islands, SCA level winds are very likely (80-90% chance) late Monday into early Wednesday, with a 40-50% chance of GALE strength winds at the peak of the Santa Ana Wind event. It appears that the winds will be strongest Tuesday morning into the early afternoon hours.

There is a 60-70% chance of offshore SCA level wind gusts from the Port of LA to Catalina Harbor. There is a similar chance of breaking waves and/or minor coastal flooding for east facing harbors - such as Avalon and Smugglers Cove.

BEACHES
07/250 AM.

High astronomical tides approaching 7 feet during the early morning hours will bring a chance of moderate coastal flooding to southwest California shores late next week and next weekend.
Normally dry beach walkways and parking lots may see tidal overflows and minor coastal flooding. There is a chance that beach erosion may occur. Rip current activity may increase during the run up to high tide.

FIRE WEATHER
07/417 PM.

North to northeast winds will continue to weaken through the afternoon. Dry air is in place with many areas away from the coast seeing humidities in the 8 to 15 percent range. The flow will turn more west to northwest on Sunday, with some recovery of humidity, especially coastal and valley areas.

As surface high pressure builds into the Great Basin, Santa Ana winds are expected to increase late Monday morning into afternoon, then peak Monday night into Tuesday. Offshore winds are expected to diminish some by Wednesday, but very dir will persist. With the strong likelihood of widespread single digit humidities with this event, confidence is increasing for a long duration Red Flag event. In addition, there is the potential for a high end Red Flag event across some of the windiest areas Monday night through Tuesday, as localized wind gusts of 55 to 70 mph could overlap with single digit humidities across the western San Gabriels, Santa Susanas, western Santa Monicas, Ventura county valleys, and the hills above Camarillo. Dry offshore conditions will likely persist into Thursday.

LOX WATCHES/WARNINGS/ADVISORIES
CA...Red Flag Warning in effect from 10 AM Monday to 6 PM PST Wednesday for zones 288-358-369>380-548. (See LAXRFWLOX).
Fire Weather Watch in effect from Monday evening through Tuesday evening for zone 345. (See LAXRFWLOX).
Red Flag Warning in effect from 2 PM Monday to 2 PM PST Wednesday for zones 354-355-362. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 4 AM PST Monday for zone 670. (See LAXMWWLOX).
Small Craft Advisory in effect until 9 AM PST Sunday for zone 673. (See LAXMWWLOX).