18/1224 PM.
Dry and warm conditions through Monday. Locally breezy offshore flow today, turning onshore next week. A weak to moderate storm system will bring widespread rain Monday Night through Tuesday, focused over San Luis Obispo and Santa Barbara Counties. Impacts will generally be minor. Widespread gusty west to northwest winds to follow Wednesday through Friday.
(tdy-Tue), 18/1226 PM.
The quick round of offshore flow will transition back to onshore flow sundown. While temperatures will drop a bit Sunday and Monday as a result, high pressure aloft will linger and will keep temperatures above normal. Coastal areas will be at the mercy of the marine layer. While low clouds are pretty minimal at the moment, onshore surface pressure gradients are in line to be neutral Sunday morning which usually is a recipe for some dense fog after an offshore spell. Always a difficult call. The onshore shift will also spin up some gusty southwest winds over typical interior areas. Wind Advisories are unlikely, but gusts in the 25 to 35 mph should be expected each afternoon. Look for ample high clouds to stream over the area tonight into Sunday.
A low pressure system, currently centered above 500 miles west of Washington state, will cutt off from the prevailing jet and slowly move south through Sunday, eventually settling just off the northern California coast for Monday and Tuesday. Warm and moderately moist (pwats around 1 inches) southwest flow on the east side of the low will produce a slow moving band of rain over northern and central California with a potential for notable impacts up there. As the band moves to the south and through Ventura and Los Angeles Counties later Tuesday, it will be a shell of itself having lost most of its energy. Any rain will be light (0.10 to 0.33 inches) with good model agreement on that. For San Luis Obispo and Santa Barbara Counties however, they are squarely in between these two scenarios with a range of outcomes. The majority of the solutions and the most likely scenario calls for moderate amounts, generally 0.50 to 1.00 inches except 1 to 2 inches for favored foothills and mountains. There are however about 20% of the projections that show 1.5 to 2.0 times those amounts, which includes a 5-10% chance of thunderstorms. If the most likely outcome plays out, rates of 0.10 to 0.33 inches per hour will be common and impacts will be generally minor (slick roads and wet outdoor events). If the higher-end scenario plays out, it still would not result in major impacts, but some localized minor to moderate flooding impacts would be added to the table, focused over the roads.
Snow levels look to stay above 6,500 feet so snow impacts will be minimal to none. South to southwest winds will bring gusts of 20 to 40 mph to parts of the area, especially over the mountains and much of San Luis Obispo and Santa Barbara Counties. High temperatures will obviously fall, with 60 to 70 fairly common.
(Wed-Sat), 18/1224 PM.
The closed low that will bring rain on Tuesday will open up and move to the northeast on Wednesday. Some projections have a weak shortwave rotating around the low and through San Luis Obispo and Santa Barbara Counties. If this ends up happening, a few scattered showers would be around on Wednesday (about a 20% chance). These showers do not look convective and any impacts would be minor.
Winds will be on the rise for the back half of next week. Most projections show a classic post-frontal west to northwest wind push on Wednesday and Thursday, with fairly widespread gusts of 25 to 45 mph focused over coastal, mountain, and desert areas. The winds become more northwesterly later Thursday and Friday as a weak inside slider moves through, with winds focused over the more typically windy areas. Saturday could see continued northwest winds, or some solutions show the inside slide retrograding west and over our area. Temperatures will recover some for the end of the week, but just to about normal for this time of the year.
18/1749z.
At 1631Z at KLAX, the marine layer was 1100 ft deep. The top of the inversion was at 1500 ft with a temperature of 18 C.
High confidence in VFR conditions for all sites through 06Z.
Chances for V/LIFR conditions from 10Z-15Z: KSMX (40%), KSBP (25%), KSBA (20%), KOXR (20%) & KLAX/LGB (15%).
KLAX, Moderate confidence in TAF. VFR conditions are expected. However, there is a 15% chance of V/LIFR conditions from 10-16Z. No significant east wind component expected.
KBUR, High confidence in VFR TAF. No wind issues expected.
18/757 AM.
High confidence in winds and seas remaining below Small Craft Advisory (SCA) levels through Sunday. A system will move through the coastal waters Monday through Wednesday morning bringing the chance for showers mainly north of Point Conception. Cannot rule out a thunderstorm or two across the northern waters Monday afternoon through Tuesday morning.
SCA level winds are possible along the cold front. By Wednesday afternoon into the evening hours, SCA level NW winds will develop south of Point Conception. These winds will likely expand to include the majority of waters by Thursday afternoon. SCA winds may persist into the weekend at least for some waters.
Ca, NONE. PZ, NONE.
