23/223 PM.
Mild weather is expected through the weekend, with daytime highs generally within a few degrees of normal. May gray low clouds and fog will spread over the coasts and valleys each night through morning period. Monday into at least the middle of next week, well below normal temperatures are likely with areas of gusty evening winds.
(Sat-Tue), 23/806 PM.
***UPDATE***
The marine inversion early this evening at LAX was around 1700 ft deep and is expected to deepen tonight probably to near 2500 ft deep or so by daybreak. Low clouds from this morning finally dissipated and pushed off the coast by mid afternoon for most areas, with just a few locations along the coast remaining overcast into the evening.
The low clouds are forecast to redevelop and expand over the coastal waters to the coast this evening and back into the vlys overnight, including the Santa Clarita Vly and the southern Salinas River Vly into SLO County. Otherwise and elsewhere, mostly clear skies will prevail across the region thru the night. The breezy to gusty onshore winds of early this evening will abate with generally light winds for most areas overnight.
***From Previous Discussion***
Beside areas of gusty winds, benign weather conditions are expected through the forecast period. A very deep marine layer is expected through Monday, with overnight-to-morning low clouds and fog overspread across all the coasts and valleys, including Santa Clarita and Paso Robles. Afternoon sunshine is favored for the majority of areas, however some beaches may stay socked-in all day, and there is a chance of reverse clearing in LA county (where clouds linger longer in the valleys than the beaches).
Temperatures will be within a few degrees of normal for most areas with little change each day through Monday. Expect highs in the upper 60s to upper 70s across the coasts and most valleys, and mid to upper 80s for the Antelope Valley and Cuyama. A rather strong low pressure system is expected to drop into the Great Basin starting on Tuesday, and the cold air advection will cool temperatures. Highs will fall to 5 to 10 degrees below normal (mid 60s to mid 70s common) on Tuesday.
Breezy southwest winds will occur across far interior San Luis Obispo County and the Antelope Valley, though will likely stay below advisory levels through Sunday. Winds will increase Monday and Tuesday as surface pressure gradients peak and the approaching low increases northwest flow across the area. Wind Advisories may be needed Monday and Tuesday for the southwesterly winds in the Antelope Valley and northwesterly winds across Southwestern Santa Barbara County. Wind will also be elevated on Tuesday afternoon and evening along the Central Coast.
(Wed-Sat), 23/236 PM.
Cold northwesterly flow aloft overnight may break down the marine inversion, which would allow for patchy marine layer clouds Wednesay and Thursday mornings and faster clearing of low clouds during the day. However the low pressure system may shuttle in some high clouds into the region. When the low is closest and 500 mb heights bottom out, there will be some cooling for areas across the interior (like the Antelope Valley). Thus highs regionwide will be in the mid 60s to low 70s Wednesay and Thursday. Starting Friday temperatures will trend upwards and the low travels to the east, becoming within a few degrees of normal on Saturday (highs in the low 70s to low 80s across the coasts and valleys).
Surface pressure gradients will remain moderate-to- strongly onshore through at least next Saturday. Thus some amount of May Grey overnight to morning clouds will continue each day, and gusty near advisory level southwest winds will occur each evening across the Antelope Valley.
24/0109z.
At 0024Z at KLAX, the marine layer was 1400 feet deep. The top of the inversion was at 3200 feet with a temperature of 18 degrees Celsius.
For the 00Z TAFs, high confidence in KWJF and KPMD. For all other sites, moderate confidence in forecasts as flight category changes could be up to +/- 3 hours of current forecasts.
KLAX, Moderate confidence in the 00Z TAF. Flight category changes could be +/- 2 hours of current forecasts. No significant easterly wind component is expected.
KBUR, Moderate confidence in the 00Z TAF. Flight category changes could be +/- 2 hours of current forecasts.
23/823 PM.
For the Outer Waters, moderate to high confidence in current forecast. Through Monday afternoon, high confidence in winds and seas remaining below Small Craft Advisory (SCA) levels. Monday afternoon expect increasing NW winds, then starting Tuesday, high confidence in both winds and seas increasing to SCA levels. Additionally, there is a 30-40% chance of Gale force winds Tuesday night. For Thursday afternoon and Thursday night, conds are likely to drop below SCA levels across the waters.
For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. Through Monday afternoon, high confidence in winds and seas remaining below SCA levels. There is a 30% chance of SCA level winds Monday afternoon and evening. For Tuesday through early Wednesday, high confidence in a combination of SCA level winds (strongest in the afternoon and evening hours) and seas. Additionally, there is a 20-30% chance of Gale force winds Tuesday afternoon and especially Tuesday night. For Wednesday afternoon through Thursday night, conds should drop below SCA levels.
For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. Through Monday night, high confidence in winds and seas remaining below SCA levels. Tuesday and Tuesday night, there is a 40-60% chance of SCA level winds across the western half of the Santa Barbara Channel and a 30-40% chance of SCA winds over PZZ655 Tuesday night. Otherwise, moderate to high confidence in winds and seas remaining below SCA levels.
Ca, NONE. PZ, NONE.
