textproduct: Los Angeles

SYNOPSIS

08/231 AM.

A significant southerly swell will bring hazardous surf conditions to the beaches through at least Tuesday. Isolated showers will continue at times through Tuesday. The combination of increasing heat and humidity across the area will cause moderate to major impacts, focused over the coasts and valleys Tuesday through at least Thursday.

LONG TERM (SAT-TUE)

08/138 PM.

For the extended, 12Z models continue to exhibit good synoptic agreement through the extended period. At upper levels, the ridge will remain flat through Monday, then may start to strengthen a bit on Tuesday. At the surface, weak to moderate onshore pressure gradients are expected.

Forecast-wise, the above pattern will result in rather benign weather through the period. Skies should remain mostly clear for most areas with some stratus/fog likely returning to the coastal plain during the night/morning hours. As for temperatures, there will be minor day-to-day fluctuations in temperatures, but the area will be about 3-6 degrees below normal. With atmospheric moisture also decreasing, conditions will be rather comfortable and no heat issues are expected.

AVIATION

09/0124Z.

At 0033Z at KLAX, there was no marine layer nor inversion.

Low to moderate confidence in TAFs due to uncertainty in low cloud formation overnight. The presence of tropical moisture in the area may result in clouds struggling to form over the Central Coast sites, with a 40 percent chance of no low clouds (meaning conds remain VFR) at KSMX and KSBP overnight. If cigs do form, there is a 40 percent chance of LIFR conds at KSBP 06Z-17Z.

For sites south of Point Conception, there is a 30% chance of brief, intermittent MVFR conds, and possible local fog formation overnight.

KLAX...Low to moderate confidence in TAF. There is a 30% chance of brief, intermittent BKN008-012 conds, and possible local fog formation overnight. No significant east wind component expected.

KBUR...Low to moderate confidence in TAF. There is a 30% chance of brief, intermittent BKN008-012 conds, and possible local fog formation overnight.

MARINE

08/128 PM.

There continues to be a slight chance of thunderstorms over the waters through this evening, with a cluster of storms currently moving to the northeast through large portions of the waters south of Point Sal. Smaller yet nonzero chances exist Wednesday.

Good confidence in winds and seas increasing to Small Craft Advisory (SCA) levels this afternoon focused south and west of Point Sal, with moderate confidence in winds increasing across all Outer Waters by Wednesday at the earliest. Winds and at times seas will likely exceed SCA levels into early next week.

Across the nearshore waters along the Central Coast, winds will locally reach SCA levels today and tomorrow, with more expansive gusty winds Thursday into early next week, with SCAs likely to be issued.

South of Point Conception, moderate confidence in SCA winds across the western half of the Santa Barbara Channel (locally eastern portions) each afternoon and evening into early next week. Thus, there is a 40-60% chance for SCAs to be issued each day, with highest chances today and again this weekend. Local SCA gusts will be possible each afternoon-evening across the Santa Monica Bay and San Pedro Channel into early next week with highest chances today.

The southerly swell that has impacted the coastal waters over the last few days will continue to gradually subside through tonight and tomorrow.

BEACHES

08/123 PM.

There is a slight chance of thunderstorms across all beaches into this evening. Any thunderstorm that forms could produce local gusty and erratic winds, brief heavy downpours, and dangerous cloud-to-ground lightning. Low but nonzero thunderstorm chances exist Wednesday.

A south swell from post tropical cyclone Marie is subsiding, but continued coastal impacts are likely through at least tonight. High surf will continue through tonight, gradually decreasing as the southerly swell decreases. Highest surf is still expected across south facing coasts across LA/Ventura Counties, esepcailly near Zuma Beach and the Long Beach coastline. Very strong and dangerous rip currents will continue as well.

Moderate coastal flooding has occurred and minor to locally moderate coastal flooding will continue through Thursday around evening high tides for south facing shores as the swell decreases, but tides remain very high. The actual observed tides have been running about 6 inches above predictions, with the evening tides near or exceeding 7 feet.

Expect continued beach erosion, flooded sandy beach areas, bike paths, and parking lots, as well as low-lying roads. Some areas that may continue to see impacts are: the Alamitos Peninsula in Long Beach, Avalon on Catalina Island, and Oxnard to Malibu (including the Pacific Coast Highway near Point Mugu).

Beach Hazards Statements (BHS) have been issued for the beaches of Los Angeles and Ventura Counties following the expiration of the Coastal Flood Advisories due to the very high evening tides Wednesday and Thursday. There will be some lingering southerly swell into Wednesday.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Extreme Heat Warning in effect from 8 AM Wednesday to 8 PM PDT Thursday for zones 38-87-88-340>358-362-366>375-548. (See LAXNPWLOX). Coastal Flood Advisory in effect until 11 PM PDT this evening for zones 87-354-362-366. (See LAXCFWLOX). High Surf Advisory in effect until 11 PM PDT this evening for zones 87-354-362-366. (See LAXCFWLOX). Beach Hazards Statement in effect from 11 PM PDT this evening through Thursday evening for zones 87-354-362-366. (See LAXCFWLOX). Beach Hazards Statement in effect until 11 PM PDT this evening for zones 340-346. (See LAXCFWLOX). Beach Hazards Statement in effect through Thursday evening for zones 349-350. (See LAXCFWLOX). Heat Advisory in effect until 8 AM PDT Wednesday for zones 362-366>373-548. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 9 PM PDT this evening for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zones 673-676. (See LAXMWWLOX).