Area Forecast Discussion

SYNOPSIS

21/1251 PM.

Unsettled weather will continue through this evening before the departing low pressure system allows some warming through Friday. Gusty northwest to north winds are possible in the storms wake, especially for Wednesday afternoon to evening. A weak storm with light rain is possible sometime this weekend.

SHORT TERM (TDY-FRI)

21/103 PM.

The front that brought much of the rain to areas up north as weakened significantly with scattered light showers focused ahead of it in Los Angeles and Ventura Counties. Behind the front isolated scattered showers will continue especially for northern Santa Barbara County to San Louis Obispo County through this evening. There continues to be a 10-20 percent chance of thunderstorms focused across San Luis Obispo County through this afternoon. Brief heavy downpours, gusty winds up to 40 mph, and cloud- to- ground lightning are the most likely hazards with any thunderstorms. The threat for moderate rain rates as largely ended, although very isolated hourly rates around a quarter to half of an inch per hour is possible through this evening with any thunderstorms.

Gusty southwest winds should dissipate this evening, allowing ongoing wind advisories to end. Additional wind advisories may be needed Wednesday afternoon through Thursday morning focused across Southern Santa Barbara County, much of Ventura County, and western Los Angeles County. Winds will dissipate by Friday but remain breezy in some areas especially in the afternoon to early evening hours.

The departing low pressure system will allow gradual warming of 4-8 degrees through Friday, approaching seasonal temperatures.

LONG TERM (SAT-TUE)

21/1252 PM.

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

21/1219 PM.

For the Outer Waters, moderate to high confidence in current forecast. Through Wednesday morning, high confidence in winds and seas remaining below Small Craft Advisory (SCA) levels. From Wednesday afternoon through Friday night, high confidence in SCA level northwest winds. Additionally, there is a 20-30% chance of GALE force winds Wednesday night, south of Point Conception. For Saturday through Sunday, 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. Through Wednesday morning, high confidence in winds and seas remaining below SCA levels. From Wednesday afternoon through Friday, there is a 60-80% chance of SCA level winds in the afternoon and evening hours. For Saturday through Sunday, 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. Through Wednesday morning, high confidence in winds and seas remaining below SCA levels. For Wednesday afternoon through Wednesday night, high confidence in SCA level winds across all the southern Inner Waters. For Thursday through Friday, there is a 50-70% chance of SCA level winds across the western half of the Santa Barbara Channel in the late afternoon and evening hours. For Saturday through Sunday, high confidence in winds and seas remaining below SCA levels.

Widely scattered thunderstorms will be possible through early this evening across the waters north of Point Conception. Brief heavy rain, gusty winds and locally rough seas will be possible with any thunderstorms.

LOX WATCHES / WARNINGS / ADVISORIES

CA...Wind Advisory in effect until 5 PM PDT this afternoon for zones 376-377. (See LAXNPWLOX). Wind Advisory remains in effect until 10 PM PDT this evening for zones 378>383. (See LAXNPWLOX). PZ...Small Craft Advisory in effect from 3 PM to 9 PM PDT Wednesday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM Wednesday to 3 AM PDT Thursday for zones 650-655-670-673-676. (See LAXMWWLOX).