21/222 AM.
Light to moderate rain is expected through today, although locally heavier rain is possible over the northern area. The highest rain amounts are expected for San Luis Obispo County, however with minimal impacts. Much cooler weather is on tap through Wednesday. Gusty southwest winds are expected today, followed by west to northwest winds Wednesday through Friday.
(tdy-Thu), 21/221 AM.
A moderate late season storm will move across Southwest California through today. Most of the rain will occur this morning through this evening, however some light showers may linger over the northern mountain slopes tonight into early Wednesday. The highest rain amounts will cover San Luis Obispo and Santa Barbara Counties, as the front will weaken as it moves over Ventura County and especially Los Angeles County. There will be a slight chance of thunderstorms from 400 AM today through the afternoon hours over San Luis Obispo County. While there is a chance of locally heavier rain at times across much of the area, this will be enhanced over SLO county due to the convective chances.
Rainfall totals will range from one quarter of an inch to around an inch for San Louis Obispo (except for 1.5-2 inches for the coastal hills) and Santa Barbara Counties, to 0.5 inch in the Ventura Mountains, to one third of an inch or less elsewhere. Brief heavy downpours, gusty winds up to 40 mph, and cloud-to- ground lightning are the most likely hazards with any thunderstorms. Peak rainfall rates will be around a quarter of an inch per hour or less, although rates up to 0.5 inches per hour many occur in any thunderstorms or along the frontal boundary. Minor flooding is possible if these rates occur, especially in low lying urban areas or near recent burn scars.
As for winds, gusty south to southwest winds are expected ahead of and near the front, generally 20 to 40 mph. Stronger SW winds will affect the Antelope Valley and San Gabriel Mountains from around 10 AM today through this evening. After this time, winds will shift to the west to northwest and remain gusty into Thursday. These winds will be strongest over the mountains and interior, but may affect some coastal sections at times.
(Fri-Mon), 21/540 AM.
Friday will offer another day of near normal temperatures mostly in the 70s. 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.
21/1207z.
At 0743Z at KLAX, the marine layer was 1500 ft with a weak inversion up to 2100 ft with a maximum temperature of 13 C.
Low to moderate confidence, as a front with a line of showers moves from north to the south across the area. Timing of rain and flight category changes could be +/- 2 hours of current forecasts. There will be a 10-15% chance of thunderstorms through 00Z Wed at KPRB, KSBP, and KSMX.
KLAX, High confidence in return of CIG/VSBY restrictions, but timing of rain and flight category changes could be +/- 2 hours of current forecast. There is a 30% chance for an easterly wind component of around 5-6 kt through 18Z.
KBUR, High confidence in return of CIG/VSBY restrictions, but timing of rain and flight category changes could be +/- 2 hours of current forecast.
21/211 AM.
For the Outer Waters, moderate to high confidence in current forecast. Ahead of the front, there is potential for short-lived SCA level winds through this morning, with best chances from the Channel Islands northward. Seas will be near 10 feet through today. For Wednesday through Friday, high confidence in combination of SCA level northwesterly winds and seas with a 20-30% chance of GALE force winds south of Point Conception Wednesday night. For Saturday, 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. Ahead of the front, there is potential for short-lived SCA level winds through this morning, with best chances from the Channel Islands northward. Seas will be near 10 feet through today. For Wednesday through Friday, there is a 60-80% chance of SCA level northwesterly winds, mainly in the afternoon and evening hours. On Saturday, 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. This morning, winds and seas should mostly remain below SCA levels, but localized gusts near the front may briefly reach SCA levels. On Wednesday, high confidence in SCA level northwesterly across all the southern Inner Waters with a 20% chance of GALE force winds. For Thursday through Friday, winds and seas are expected to remain below SCA levels for most areas. The only exception will be the western half of the Santa Barbara Channel with a 60-80% chance of SCA level winds. On Saturday, high confidence in winds and seas remaining below SCA levels for all of the southern Inner Waters.
A cold front will sweep across the coastal waters through today. With this frontal passage, there will be a 20% chance of thunderstorms across the coastal waters north of Point Conception. Any thunderstorms that develop may produce brief heavy rain, gusty winds and locally rough seas.
Ca, Wind Advisory in effect from 10 AM this morning to 10 PM PDT this evening for zones 378>383. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 6 PM PDT this evening for zones 645-670. (See LAXMWWLOX).
