textproduct: Los Angeles

SYNOPSIS

15/1247 PM.

A moderate to strong Santa Ana Wind will bring widespread strong winds and 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 is expected Sunday with a chance of widespread rain by Tuesday or Wednesday.

LONG TERM (MON-THU)

15/230 PM.

More cooling is in store on Monday as an upper low moves down the coast. Hgts will fall from 580 dam Sunday afternoon to 576 dam Monday afternoon. Actual onshore flow will develop and will increase through the day. Some morning marine layer clouds may even develop over the Central Coast. Max temps will fall 4 to 8 degrees. This will bring max temps down to near normals.

There is increasing confidence in rain chances next week, though timing is still quite uncertain as are the amounts. Virtually all the solutions from the ENS and GEFS ensembles indicate at least some light rain, most likely starting Wednesday, but could start as early as Tuesday afternoon or as late as Wednesday evening. Rain amounts are even more scattered but mostly around a half inch area-wide. It's a tricky pattern with the upper low dropping south along the California coast and a lot of uncertainnesshow far offshore and where it will turn inland. Might take another few days to have more confidence in amounts and timing. There are more than a few solutions that bring an inch or more so this needs to be followed closely, especially with the possibility of brush fires during the current strong Santa Ana winds.

AVIATION

16/0247Z.

At 00Z at KLAX, there was no marine layer or inversion.

For 00Z TAF package, high confidence in CAVU conditions for all sites through the period. Moderate confidence in direction/strength of northeast- east winds, gusts may be off by 030 degrees and 10-15 knots respectively.

KLAX...High confidence in 00Z TAF with CAVU conditions expected through the period. Moderate to low confidence in winds, and there is the potential for an extended period of gusty easterly winds from about 18 to 23Z, with gusts up to 25 kt.

KBUR...High confidence in CAVU conditions through the TAF period. Moderate confidence in winds as timing may be off by 2-3 hours and strength could be +/- 10 knots.

MARINE

15/1215 PM.

For the Outer Waters, moderate to high confidence in current forecast. Today through Sunday, high confidence in winds and seas remaining below Small Craft Advisory (SCA) levels across PZZ670/673. For PZZ676, there is a 60-80% chance of SCA level winds late tonight and Friday. On Monday and Tuesday, there is a 50-60% chance of SCA level winds across all of the Outer Waters with seas hovering around SCA levels.

For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. Through tonight, high confidence in winds and seas remaining below SCA levels. On Friday, there is a 50% chance of SCA level northeast winds. For Saturday and Sunday, high confidence in winds and seas remaining below SCA levels. On Monday and Tuesday, there is a 50% chance of SCA level winds, mainly in the afternoon and evening hours with seas hovering near SCA levels.

For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. Through tonight, high confidence in SCA level northeast winds from Ventura south to Santa Monica with winds/seas remaining below SCA levels elsewhere. On Friday, there is a 60-70% chance of GALE force winds from Ventura to Santa Monica with a 40-60% chance of SCA level winds elsewhere (especially across the San Pedro Channel). For Friday night and Saturday, there is a 50% chance of SCA level northeast winds from Point Mugu to Santa Monica with high confidence in winds and seas remaining below SCA levels elsewhere. For Sunday through Tuesday, high confidence in winds and seas remaining below SCA levels for most areas except for the western half of the Santa Barbara Channel where there is a 50-60% chance of SCA level winds.

FIRE WEATHER

15/1224 PM.

Moderate to strong offshore flow will peak around Friday, then slowly weaken through the weekend. During the peak, northeast winds of 20 to 40 mph with gusts to 50 to 70 mph will be common over the wind prone areas of Los Angeles and Ventura Counties, with localized gusts of 70 to 90 mph in the mountains. On Friday, winds will be unusually widespread affecting most of our area including areas that typically do not see Santa Ana winds. This includes much of Santa Barbara and San Luis Obispo Counties, 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 90 and 100 will be common by Friday, warmest near the coast where the risk for heat illness is high. Minimum humidities will generally lower into the 8 to 20 percent range, with poor overnight recoveries.

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 the mountains and foothills of San Luis Obispo and Santa Barbara Counties where Red Flag Warnings are in place. While some areas received rain earlier this week, the dry day today will largely remove any benefiting effects on the fuels.

Residents in high fire risk areas should be prepared in case a fire starts. Review your evacuation plans...what would you bring, where would you go. Stay extra aware of your surroundings. Make sure your vehicle is fueled up. For everyone, avoid using anything that could spark a fire. Be prepared for power outages that are likely over a good portion of our areas.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Wind Advisory in effect until 8 PM PDT Friday for zones 88-354-355-358-362-370>374-376-377. (See LAXNPWLOX). Heat Advisory in effect until 8 PM PDT Saturday for zones 340-341-346-347-349-350-354-355-362-366>368. (See LAXNPWLOX). High Wind Warning in effect until 8 PM PDT Friday for zones 369-375-378>380. (See LAXNPWLOX). Red Flag Warning in effect until 8 PM PDT Saturday for zones 288-354>358-362-369>382-548. (See LAXRFWLOX). Red Flag Warning in effect from 3 AM to 6 PM PDT Friday for zones 342-345-353. (See LAXRFWLOX). PZ...Small Craft Advisory in effect until 3 AM PDT Friday for zones 650-655. (See LAXMWWLOX). Gale Warning in effect from 3 AM to 5 PM PDT Friday for zones 650-655. (See LAXMWWLOX). Small Craft Advisory in effect from 2 AM to 5 PM PDT Friday for zone 676. (See LAXMWWLOX).