textproduct: Los Angeles

SYNOPSIS

14/756 PM.

A moderate to strong Santa Ana Wind event kicks off tomorrow, bringing widespread critical fire weather conditions to much of Southwest California through Saturday. Additionally, very warm temperatures bring a high risk of heat illness to all coastal areas. A significant cool down with a chance of widespread rain is expected next week.

LONG TERM (SUN-WED)

14/201 PM.

A rapid cooling trend is expected to begin Sunday for coastal areas as a low pressure system moving into the Pac NW initiates strong return to onshore flow. Coastal areas will drop 10-15 degrees from Saturday and could see a return of low clouds and fog as early as Monday. Valleys and other interior areas will maintain their respective temperatures through around Monday before the cooling finally arrives with the next storm system on Tuesday.

There is still quite a bit of uncertainty with the track of that system. Models initially had it moving much farther inland but later solutions have trended more to the west. Roughly 20-30% of the current solutions show some light rain chances as early as late Tuesday, but there are just as many solutions holding off until as late Thursday due to the storm tracking even farther off the coast. Either way, there is high confidence in a much cooler pattern by the middle of next week.

AVIATION

15/0212Z.

At 00Z at KLAX, there was no marine layer nor inversion.

High confidence in CAVU TAFs, moderate confidence in winds. Timing and strength of gusty NE winds may be off by 2-3 hours and 10kt respectively.

KLAX...High confidence in CAVU TAF. Any east wind component will be AOB 7 kts 10Z-16Z. Light east winds are again possible by Friday 03Z.

KBUR...High confidence in CAVU TAF. Moderate confidence in winds, and N to NE winds may begin as early as 10Z.

MARINE

14/216 PM.

Santa Ana Winds will affect our inner waters south of Point Conception Thursday through Saturday morning. Strongest during the late night into early afternoon hours. These hazardous NE-E winds will be focused from Ventura to Santa Monica and out past Anacapa Island. These winds could become hazardous across the San Pedro Channel Friday morning with a 25% chc of 25 kt gusts at Avalon Harbor. The worst conditions are expected Friday morning with the most concern nearshore from Ventura-Malibu. Gale Watches have been issued to target these waters. Refer to MWWLOX for more details. Small Craft Advisory (SCA) may be needed for the nearshore waters along the Central Coast Friday morning due to gusty offshore winds.

There is a solid signal for a trough early to mid next week which could bring hazardous boating conditions along with rain chances to our coastal waters. Will monitor this system.

Long period swells 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.

FIRE WEATHER

14/909 AM.

Offshore flow will steadily increase each day through Thursday or Friday, then weaken over the weekend. During the Thursday and Friday peak, northeast winds of 20 to 40 mph with gusts to 40 to 60 mph will be common over the wind prone areas of Los Angeles and Ventura Counties, with localized gusts of 60 to 70 mph in the mountains. Winds will be unusually widespread on Friday, when much of Santa Barbara and San Luis Obispo will experience a few hours windy conditions, especially the interior mountains where winds of 15 to 25 mph and gusts of 30 to 40 mph are expected. Meanwhile, the air will rapidly warm and dry. High temperatures between 85 and 95 will be common by Friday, warmest near the coast where the risk for heat illness is high. Minimum humidities will generally lower into the 5 to 15 percent range by Friday, with poor overnight recoveries starting Thursday.

All of this will add up to a high risk for large fires and rapid fire growth over most of the area, especially over Los Angeles and Ventura Counties as well as interior San Luis Obispo and Santa Barbara Counties where Red Flag Warnings and Fire Weather Watches are in place. While some areas received rain earlier this week, the dry day today will largely remove any benefiting effects on the fuels.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Wind Advisory in effect from 6 AM Thursday to 8 PM PDT Friday for zones 88-354-355-358-362-370>374-376-377. (See LAXNPWLOX). Heat Advisory in effect from 10 AM Thursday to 8 PM PDT Saturday for zones 340-341-346-347-349-350-354-355-362-366>368. (See LAXNPWLOX). Beach Hazards Statement in effect through Thursday afternoon for zones 354-362-366. (See LAXCFWLOX). High Wind Warning in effect from 6 AM Thursday to 8 PM PDT Friday for zones 369-375-378>380. (See LAXNPWLOX). Red Flag Warning in effect from 6 AM Thursday to 8 PM PDT Saturday for zones 288-354-355-358-362-369>382-548. (See LAXRFWLOX). Red Flag Warning in effect from 3 AM to 6 PM PDT Friday for zones 345-353. (See LAXRFWLOX). PZ...Small Craft Advisory in effect from 9 AM to 3 PM PDT Thursday for zones 650-655. (See LAXMWWLOX). Gale Watch in effect from late Thursday night through Friday afternoon for zones 650-655. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zones 673-676. (See LAXMWWLOX).