04/836 PM.
Temperatures will be slightly above normal inland and near normal along the coast through Friday, then dropping below normal over the weekend and into next week as a large low pressure system develops over the West coast. Skies will be mostly clear except for night and morning low clouds and fog across the coast and valley areas.
(Thu-Sun), 04/815 PM.
***UPDATE***
Today was very similar to yesterday, with perhaps a bit less marine layer clouds and fog. The interior wanted into the 90s to 100 degrees, and cool 60s and 70s near the coasts. Friday should see very similar temperatures, with heights falling slightly. Expecting another round of marine layer clouds with patchy fog overnight and into Friday morning, and some areas may fail to clear in the afternoon hours. Low pressure brings a cooling trend Saturday and a deepening, large expansion of the marine layer. Aside from cooling temperatures along the Central Coast over the next few days, the forecast looks on track.
***From Previous Discussion***
Overall a very similar day today as yesterday with low clouds lingering near the beaches between Malibu and Santa Barbara and warmer valleys in the lower 90s. A very typical June day across southwest California.
A large upper low currently just west of the BC coast is expected to slide south into the Pac NW this weekend, lowering heights across California and cooling temperatures, especially inland. By Sunday most areas will be 2-5 degrees below normal. Forecast soundings indicate the marine layer will top out around 2500 feet over the weekend but given the cooling aloft would not be surprised to see it 3000 feet or higher. Low clouds are expected to move into all coast and valley areas overnight and clear to near the beaches each afternoon.
Northerly flow is expected to weaken the next couple days leading to less wind across southwest Santa Barbara County and the I5 corridor. However, models are favoring a return of Sundowners Sunday evening with a 3-4mb gradient from the north.
(Mon-Thu), 04/205 PM.
The upper low over the Pac NW this weekend is expected to be followed by yet another low pressure system early next week, maintaining a trough pattern along the West coast and cooler than normal temperatures. There are even a few ensemble solutions showing a cold upper low as far south as Fresno next Tuesday with a weak cold frontal passage. However, a vast majority of the solutions favor most of that energy staying well to the north with just a weak upper trough over the area through mid week and slowly warming temperatures but still either near to slightly below normal. There are some signals for weakening onshore flow or even weak offshore flow starting next Wednesday or Thursday that would lead to additional warming but most of the ensembles keep gradients at least slightly onshore with a more gradual warming trend.
05/0220z.
At 2230Z at KLAX, the marine layer was 1500 feet deep. The top of the inversion was near 3200 feet with a temperature of 22 degrees Celsius.
For 00Z TAF package, high confidence in TAFs for KPMD and KWJF. For all other sites, moderate confidence due to uncertainties with the marine layer. Timing of flight category changes could be +/- 3 hours of current forecasts. Cigs may fail to clear in the afternoon/evening hours near the coasts.
KLAX, Moderate confidence in 00Z TAF. Timing of flight category changes could be +/- 3 hours of current forecasts. No significant easterly wind component is expected.
KBUR, Moderate confidence in 00Z TAF. Timing of flight category changes could be +/- 3 hours of current forecasts. There is a 30% chance that CIG/VSBY restrictions do not develop tonight.
04/836 PM.
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 30-40% chance of GALE force winds across PZZ670 and PZZ673 on Saturday and Saturday night, especially for zone PZZ670
For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. High confidence in SCA level seas through late tonight. On Friday, 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 40-50% 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 Friday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Saturday for zones 670-673-676. (See LAXMWWLOX). Gale Watch in effect from late Friday night through late Saturday night for zone 670. (See LAXMWWLOX).
