05/817 AM.
Temperatures will remain near to slightly below normal through at least early next week as a series of low pressure systems moves through the West coast. Low clouds and fog will cover most coast and valleys through at least mid morning, clearing to near the beaches each afternoon. A warming trend is expected later next week.
(tdy-Sun), 05/829 AM.
***UPDATE***
Marine layer held at 2000 feet in LA sloping down to around 1400 feet along the Central Coast which is a little higher than yesterday. Today is expected to feel a lot like yesterday except likely a little cooler along the Central coast. Beach areas, especially from Malibu north, may not see much Sun today.
***From Previous Discussion***
A large upper level low currently situated off the British Columbia coast is expected to dive south towards PAC NW and deepen some through this weekend. This will result in the current weak ridging over our area to break down and by Sunday slightly below normal 500mb heights are expected.
Moderate onshore flow is expected to persist through the weekend both to the north and east. This in combination with decreasing heights will likely result in a 2500-3000 ft marine layer. Low clouds will have difficulty clearing near the coasts each afternoon. Marine layer stratus is most likely to cover the Santa Clarita Valley on Saturday due to LAX-BFL gradients peaking night through morning period.
A cooling trend is expected through the weekend. Most noticeable change is expected on Saturday, and along the Central Coast. By Sunday, most areas will be slightly below to below normal except across the Antelope valley where temps will cool to near normal.
There is a decent signal for low-end advisory level Sundowners Sunday evening. ECWMF and NAM indicate a 3-4mb gradient from the north.
(Mon-Thu), 05/258 AM.
The EURO and GFS ensemble suites are in agreement with another upper low diving southward but keeping the energy well to the north. Weak upper troughing will remain over the area through mid-week with slowly warming temperatures, but still either near to slightly below normal. Onshore flow to the east will persist but gradually weaken some Wednesday and beyond. While LAX-BFL projections indicate by Tuesday neutral to even weak offshore flow from the north is likely.
Potential for Advisory level Sundowners will continue at least through Wednesday evening. Most likely strongest on Tuesday. With the potential for offshore flow from the north, there is a small signal for low-end advisory winds across the I-5 corridor midweek.
05/1727z.
At 1715Z at KLAX, the marine layer was 1500 feet deep. The top of the inversion was at 3700 feet with a temperature of 23 degrees Celsius.
For 18Z TAF package, high confidence in KPMD and KWJF. For all other sites, moderate confidence in current forecast due to uncertainties in behavior of marine layer. Timing of flight category changes could be +/- 3 hours of current forecasts.
KLAX, Moderate confidence in 18Z TAF. Timing of flight category changes could be +/- 3 hours of current forecasts. There is a 40% chance that scattered conditions do not develop this afternoon. No significant easterly wind component is expected.
KBUR, Moderate confidence in 18Z TAF. Timing of flight category changes could be +/- 3 hours of current forecasts.
05/734 AM.
For the Outer Waters, moderate to high confidence in current forecast. Through Tuesday, high confidence in a combination of Small Craft Advisory (SCA) level winds and seas. Additionally, there is a 40-50% chance of GALE force winds across PZZ670 and PZZ673 on Saturday and Saturday night, especially for zone PZZ670. Therefore, a GALE WATCH is in effect for Saturday and Saturday night for PZZ670.
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. For Saturday through Tuesday, there is a 60-80% chance of SCA level winds, mainly in the afternoon and evening hours. Additionally in the Saturday through Tuesday time frame, seas will be near or above 10 feet (SCA level).
For the Inner Waters south of Point Conception, moderate confidence in current forecast. For a majority of the southern Inner Waters, high confidence in winds and seas remaining below SCA levels through Tuesday. The only exception will be the western half of the Santa Barbara Channel, where there is a 50-60% chance of SCA level winds Sunday through Tuesday, mainly in the late afternoon and evening hours.
Ca, NONE. PZ, Small Craft Advisory in effect until 3 AM PDT Saturday for zones 670-673-676. (See LAXMWWLOX). Gale Watch in effect from late tonight through late Saturday night for zone 670. (See LAXMWWLOX).
