textproduct: Los Angeles

SYNOPSIS

10/724 PM.

Moderate to damaging coastal flooding will likely continue through at least Tuesday. Periods of light to moderate rain and a low chance of thunderstorms will persist through Monday or Tuesday. Below normal temperatures will persist through Tuesday or Wednesday, then warming an developing offshore flow through the end of the week.

LONG TERM (WED-SAT)

10/1054 AM.

Wednesday will be more or less be a transition day from the cooler, active pattern to a warming and drying trend which will likely continue into the weekend. An upper level ridge of high pressure will build over the area and by Thursday we could see 500 mb heights reach 585-590 dam. Offshore flow is also poised to develop and these features will combine to bring this rapid warming and drying to southwest California. Widespread moderate heat risk is likely for the coasts and coastal valleys Thursday through the weekend, with low chances of major heat risk. The magnitude of temperatures will likely depend on the magnitude of the offshore flow, but a weak to at least locally moderate Santa Ana Wind event is likely.

AVIATION

11/0415Z.

At 0400Z at KLAX, there was neither a marine layer nor a marine inversion.

Overall, moderate confidence in 06Z TAF package. Moisture streaming northward from Tropical Storm Rachel will bring the threat of showers to all sites at times through the TAF period. The best chances for showers will be over Los Angeles county with lesser chances north and west. There is a 40% chance of MVFR CIGs at all sites through this evening. Additionally, there is a 5-10% chance of thunderstorms through this afternoon.

KLAX...Moderate confidence in 06Z TAF. There is a 40% chance of MVFR CIGs in the 15Z-02Z time frame. There is a 20-30% chance of easterly winds around 8 knots through 22Z.

KBUR...Moderate confidence in 06Z TAF. There is a 40% chance of MVFR CIGs in the 15Z-02Z time frame.

MARINE

10/756 PM.

For the Outer Waters, moderate to high confidence in current forecast. High confidence in a combination of at least SCA level winds and seas through Monday evening for the waters near and NW of Point Conception. There is a 30% chance of Gale Force winds early Sunday morning, then the winds are expected to drop below SCA levels Sunday evening. However, steep seas of 10+ feet will likely persist into at least Monday morning and possibly into Monday evening. On Tuesday, there is a 50% chance of SCA level winds around Point Conception with winds remaining below SCA levels elsewhere.

For the Inner Waters north of Point Sal, high confidence in current forecast of SCA winds through Sunday evening. There will be a chance of SCA conds again Tuesday evening, with a 30-50% chance.

For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. From this evening through Sunday evening, there is a 60-80% chance of SCA level winds and seas. For Monday through Wednesday, high confidence in winds and seas remaining below SCA levels for most of the southern Inner Waters. The exception will be the western half of the Santa Barbara Channel with a 50% chance of SCA level winds late Tuesday afternoon through Tuesday evening.

Periods of light to moderate showers are likely through Tuesday, with highest confidence for Sunday-Monday. There is a 10% chance of thunderstorms during the same time frame. While showers or thunderstorms are possible anywhere, the highest chances exist south of Point Conception.

Long period swell from the west and the south are affecting the coastal waters, and can create a confused sea state. This can make boating more challenging and dangerous, especially for small vessels.

BEACHES

10/805 PM.

Earlier this morning, LA Harbor Tide Gauge reported a peak of 7.7 feet, approximately 1.6 feet above predicted astronomical high tides.

A Coastal Flood Warning is in effect for the beaches of Los Angeles County (including Long Beach, the Malibu Coast and Catalina Island) through 3 PM Sunday. DAMAGING sea-water coastal flooding is likely through Sunday, especially near the Sunday morning high tide where anticipated tide levels are expected to be around 8 feet. The most likely areas for DAMAGING coastal flooding on Sunday morning will be vulnerable south-facing beaches due to the expected combination of very high tides around 8 feet (including additive effect of low barometric pressure and onshore winds gusting to 15 to 25 mph), high surf of 5 to 8 feet, and light to moderate rainfall. THERE IS GROWING CONFIDENCE THAT THE EXPECTED COASTAL FLOODING IMPACTS ON SUNDAY MORNING FOR VULNERABLE SOUTH FACING BEACHES OF LA COUNTY COULD BE THE MOST SIGNIFICANT WE HAVE SEEN SO FAR THIS SEASON, INCLUDING THOSE SEEN WITH Marie.

For all other beaches and harbors of LA county, minor to moderate sea- water flooding will likely impact beaches and walkways, especially with the Sunday morning high tide which could cause local damage to the most vulnerable locations such as Venice and Long Beach. For all beach areas, significant erosion is expected. There is an increased risk of ocean drowning. Dangerous and life- threatening rip currents can pull swimmers and surfers out to sea. Large breaking waves can cause injury, wash people off beaches and rocks, and capsize small boats near shore. The projected high tides of around 8 feet for Sunday morning would approach or exceed recent record tide levels for LA county. Large secondary high tides are also expected each evening.

For beaches from Ventura County northward, minor to moderate coastal flooding will be likely near times of high tide as well as periods of elevated to high surf and strong rip currents. In addition to the Coastal Flood Advisory for Ventura County, Coastal Flood Advisories have been added for the Central Coast and southern Santa Barbara coast. For Ventura county, there is the possibility of localized damage across low-lying areas during the Sunday morning high tide, along with the threat of significant sea spray and and water on sections of PCH between Point Mugu and Sycamore Cove.

A very complex series of swells from the south, west, and northwest will impact our coastlines into at least early next week. Energy from Tropical Storm Rachel, southern hemisphere swells, northwest swells, and local wind swells will add up with each other to produce the aforementioned coastal impacts. Please continue to monitor the forecast.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Coastal Flood Warning in effect until 3 PM PDT Sunday for zones 87-362-366. (See LAXCFWLOX). Coastal Flood Advisory in effect from 3 PM Sunday to 2 PM PDT Tuesday for zones 87-362-366. (See LAXCFWLOX). Beach Hazards Statement in effect until 6 AM PDT Sunday for zones 340-346. (See LAXCFWLOX). Coastal Flood Advisory in effect from 6 AM Sunday to 10 PM PDT Monday for zones 340-346-349-350. (See LAXCFWLOX). High Surf Advisory in effect from 6 AM Sunday to 10 PM PDT Monday for zones 340-346. (See LAXCFWLOX). Beach Hazards Statement in effect through Tuesday afternoon for zones 349-350. (See LAXCFWLOX). Coastal Flood Advisory in effect until 2 PM PDT Tuesday for zone 354. (See LAXCFWLOX). High Surf Advisory in effect from 6 AM to 10 PM PDT Sunday for zones 354-362-366. (See LAXCFWLOX). Wind Advisory in effect from 5 AM Sunday to 5 AM PDT Monday for zones 378>383. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 9 PM PDT Sunday for zones 645-650-655-676. (See LAXMWWLOX). Small Craft Advisory in effect until 5 PM PDT Monday for zones 670-673. (See LAXMWWLOX).