Marine Weather and Tide Forecast for Oxnard, CA

.SHORT TERM (TDY-THU)...21/932 AM.

***UPDATE***

Rainfall rates (generally under one third of an inch per hour)
and amounts (generally less than one inch) have been tracking well with forecast so far. As expected the front is weakening south of Point Conception with most areas expected less than one quarter of an inch for most of Ventura and Los Angeles Counties.

There continues to be a 10-20 percent chance of thunderstorms for San Luis Obispo County, highest northern section. We were seeing thunderstorms well off shore with shallow convection closer to the coast that may strengthen as it moves ashore and encounters daytime heating over land. Brief heavy downpours, gusty winds up to 40 mph, and cloud-to- ground lightning are the most likely hazards with any thunderstorms.

Today, we will take a look at possible wind advisories for the Wednesday to early Thursday time frame for interior mountains to potentially some coastal sections, especially in Ventura County.
The storm door may remain open into early May with mainly light rain potential at some point this weekend and again early or middle part of next week.

***From Previous Discussion***

A moderate late season storm will move across Southwest California through today. Most of the rain will occur this morning through this evening, however some light showers may linger over the northern mountain slopes tonight into early Wednesday. The highest rain amounts will cover San Luis Obispo and Santa Barbara Counties, as the front will weaken as it moves over Ventura County and especially Los Angeles County. There will be a slight chance of thunderstorms focused this afternoon over San Luis Obispo County. While there is a chance of locally heavier rain at times across much of the area, this will be enhanced over SLO county due to the convective chances.

Rainfall totals will range from one quarter of an inch to around an inch for San Louis Obispo (except for 1.5-2 inches for the coastal hills) and Santa Barbara Counties, to 0.5 inch in the Ventura Mountains, to one third of an inch or less elsewhere. Brief heavy downpours, gusty winds up to 40 mph, and cloud-to- ground lightning are the most likely hazards with any thunderstorms. Peak rainfall rates will be around a quarter of an inch per hour or less, although rates up to 0.5 inches per hour many occur in any thunderstorms or along the frontal boundary. Minor flooding is possible if these rates occur, especially in low lying urban areas or near recent burn scars.

As for winds, gusty south to southwest winds are expected ahead of and near the front, generally 20 to 40 mph. Stronger SW winds will affect the Antelope Valley and San Gabriel Mountains from around 10 AM today through this evening. After this time, winds will shift to the west to northwest and remain gusty into Thursday. These winds will be strongest over the mountains and interior, but may affect some coastal sections at times.

.LONG TERM (FRI-MON)...21/540 AM.

Friday will offer another day of near normal temperatures mostly in the 70s. Another storm system is likely to impact the area that will lead to a cooling trend over the weekend, dropping temperature back into the 60s. There is a 30-50 percent chance of mainly light rain focused across the foothills to interior sometime this weekend thanks to moist upslope flow over the mountains and limited instability. The storm energy is coming from the southwest to west and is weak so significant wind concerns are unlikely, but it does lend itself to below normal forecast confidence. Rain chances and unsettled weather may continue through the end of the month.

AVIATION
21/1647Z.

At 1630Z at KLAX, there was no marine layer or marine inversion.

Overall, low to moderate confidence in 18Z TAF. CIGs /VSBYs will bounce between VFR and IFR levels through 22Z due to light rain/showers. Confidence in timing of these changes is low. For this evening and overnight, VFR conditions are expected although there will be a 20-30% chance of MVFR CIGs /VSBYs at coastal and valley sites.

There is a 10-15% chance of thunderstorms north of Point Conception (KSMX, KSBP and KPRB) through this afternoon.

KLAX...Low to moderate confidence in 18Z TAF. With rain this afternoon, conditions will bounce between VFR and MVFR levels and confidence in timing of these flight category changes will remain low. For this evening and overnight, there is a 30% chance of MVFR CIGs /VSBYs developing in the 05Z-17Z time frame. Southeasterly winds 5-8 knots will continue through 19Z.

KBUR...Low to moderate confidence in 18Z TAF. With rain this afternoon, conditions will bounce between VFR and MVFR levels and confidence in timing of these flight category changes will remain low. For this evening and overnight, there is a 30% chance of MVFR CIGs /VSBYs developing in the 05Z-17Z time frame.

MARINE
21/712 AM.

For the Outer Waters, moderate to high confidence in current forecast. For today, Small Craft Advisory (SCA) level seas will continue across PZZ670 with winds and seas remaining below SCA levels across PZZ673/676. For Wednesday through Friday, high confidence in combination of SCA level northwesterly winds and seas with a 20-30% chance of GALE force winds south of Point Conception Wednesday night. For Saturday, high confidence in winds and seas remaining below SCA levels.

For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. For today, there is a 60-70% chance of a combination of SCA level winds and seas. For Wednesday through Friday, there is a 60-80% chance of SCA level northwesterly winds, mainly in the afternoon and evening hours. On Saturday, high confidence in winds and seas remaining below SCA levels.

For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. For today, there is a 20% chance of SCA level winds along the cold front. On Wednesday, high confidence in SCA level northwesterly across all the southern Inner Waters with a 20% chance of GALE force winds. For Thursday through Friday, winds and seas are expected to remain below SCA levels for most areas. The only exception will be the western half of the Santa Barbara Channel with a 60-80% chance of SCA level winds. On Saturday, high confidence in winds and seas remaining below SCA levels for all of the southern Inner Waters.

A cold front will sweep across the coastal waters through today.
With this frontal passage, there will be a 20% chance of thunderstorms across the coastal waters north of Point Conception.
Any thunderstorms that develop may produce brief heavy rain, gusty winds and locally rough seas.

LOX WATCHES/WARNINGS/ADVISORIES
CA...Wind Advisory in effect until 10 PM PDT this evening for zones 378>383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 6 PM PDT this evening for zones 645-670. (See LAXMWWLOX).