01/248 AM.
Onshore flow will continue to bring low clouds to the coasts and coastal valleys each night and morning. Some very light drizzle is possible each morning. Temperatures will remain well below normal for the next couple of days before a warming trend takes hold on Thursday. Many valley locations will warm into the 90s by early next week.
(tdy-Fri), 01/842 AM.
***UPDATE***
Morning satellite shows marine layer in place along the coast with multiple cloud layers, one top around 2K feet and the highest tops sitting around 3K feet. Daytime temperatures will continue to run around 10 degrees, give or take, below normal today. As upper- level heights begin to increase on Thursday, temperatures will steadily increase by a few degrees each day. The marine layer will also be thinner/quicker to dissipate further inland, meaning more sunshine to help facilitate daytime warming across many valleys. Heat risk will remain little to minor with slightly higher risk once we get to the middle of next week when daytime temperatures in our valleys warm into the 90s.
***From Previous Discussion***
June Gloom will persist into July due to the interaction of broad troffing aloft and mdt to stg onshore flow at the sfc. The marine layer has separated into two layers one around 1500 ft and another around 3000 ft. The capping inversion is not very strong and as a result the low clouds are forming in a haphazard manor. By dawn, however, most of the csts and vlys will be covered by low clouds. Burn off will be similar to ydy with some vly areas remaining cloudy as the morning stratus cooks up into an afternoon stratacu layer. Max temps will be very similar to ydys with well below normal temps esp in the vlys (8 to 12 degrees below normal).
Over Thursday and Friday the hgts will rise a little which will smoosh the marine layer down some. The onshore flow will relax a little which will allow for faster and better clearing. So look for a little less marine layer clouds (still most csts and lower vlys will have morning clouds). Max temps will rise 2 to 4 degrees each day xcp for the beaches which will only see minor warming. Even with the two days of warming Friday's max temps will still be 4 to 8 degrees blo normal.
(Sat-Tue), 01/248 AM.
Not too much change in the weather during the xtnd portion of the forecast. The overall mdl consensus is that Srn CA will be sandwiched between a large upper low to the west of British Columbia and an upper high to the SE. While the upper low will keep the flow pattern weakly cyclonic with SW flow over the area, the upper high will bring slowly rising hgts. Onshore flow at the sfc will continue but it looks to be 2 to 3 mb weaker than the short term gradients.
The rising hgts and offshore trends will reduce the marine layer in coverage and duration. Most of the csts will likely remain under constant night through morning low clouds. The vlys, however, will be sunnier.
Max temps will be on the upswing each day (maybe not the nearshore area which will see the strongest sea breeze). There will only be slight warming on Sat and Sun but early next week there could be 1 to 3 or 2 to 4 degrees of warming each day (the ensembles show a 25 percent chc of 3 to 6 degrees of warming). Max temps early next week should be in the 70s across the csts and 80s and lower 90s in the vlys. These values are only a degree or two less than normal.
Winds really should not be an issue for most of the area, but it looks like there will be gusty sub advisory level north winds across the SBA south coast each evening and overnight.
01/1628z.
At 1600Z at KLAX, the marine layer was 3700 feet deep. The top of the inversion was 5500 feet with a temperature of 16 degrees Celsius.
For 18Z TAF package, high confidence in KPMD and KWJF. For all other sites, moderate confidence in 18Z TAFs as 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 +/- 2 hours of current forecasts. There is a 30% chance that CIGs will drop to IFR levels tonight. No significant easterly wind component is expected.
KBUR, Moderate confidence in 18Z TAF. Timing of flight category changes could be +/- 2 hours of current forecasts. There is a 30% chance that CIGs will drop to IFR levels tonight.
01/706 AM.
For the Outer Waters, moderate to high confidence in current forecast. Through Thursday morning, high confidence in winds and seas remaining below Small Craft Advisory (SCA) levels. From Thursday afternoon through Sunday, there is a 40-60% chance of SCA level winds.
For the Inner Water north of Point Sal, high confidence in current forecast. Today through Sunday, winds and seas are expected to remain below SCA levels.
For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. Today through Sunday, high confidence in winds and seas remaining below SCA levels for most of the southern Inner Waters. The only exception will be the western half of the Santa Barbara Channel where there is a 20-30% chance of SCA level winds during the late afternoon and evening hours today through Sunday.
Ca, NONE. PZ, NONE.
