03/838 AM.
A weak low pressure system will bring cooler weather to the area today. It will remain cool on Monday and Tuesday with a slight chance of drizzle or a light shower. Gusty onshore winds are expected Tuesday afternoon. Dry and warmer conditions are likely Wednesday through next weekend.
(tdy-Tue), 03/851 AM.
***UPDATE***
Marine layer has deepend to at least 4000 feet this morning as the slow moving cut off low moves closer to the area, cooling temperatures aloft. There have been reports of very light measurable rain, mainly foothills south of Pt Conception. Possibly not much clearing today across coast and valleys, or at best very late. Valley highs will tumble into the 60s today, possibly some lower 70s at best.
The upper low is still well offshore but the cooling aloft may be enough to trigger some minor convection across the mountains. Those may just end up being towering cumulus but there is a 5-10% chance of a shower or brief thunderstorm this afternoon across the interior mountains.
***From Previous Discussion***
On Monday and Tuesday a 559 dam upper low will slowly approach and then move across Srn CA. PWs are only around .7 inches and there are not much dynamics with the system either, so this will not be much of a rain maker. In fact, the only areas with any real sort of chance of rain will be the mtns and the foothill regions. In other areas the upper low may provide just enough lift through the deep marine layer to squeeze out some drizzle. The mtns will likely be mostly cloudy through the period and there will be substantial marine layer clouds but there will be areas of sunshine as well esp in the afternoons.
On Monday max temps will not change much across the csts and vlys but the mtns and the far interior will see another 5 to 10 degrees of cooling. Highs in the Antelope Vly will only be in the mid 60s or 13 degrees blo normals. On Tuesday there will be some warming due to increased sunshine. The SBA south coast will warm the most (4 or 5 degrees) as some downsloping winds will develop in the wake of the low.
Later Tuesday, gusty west to northwest winds will develop, possibly near advisory levels across the Antelope Valley. At the same time somewhat weaker north winds will occur in the mtns from the I-5 corridor west to the SBA mtns.
(Wed-Sat), 03/242 AM.
Weak ridging builds into the state on Wednesday and persists through Friday before turning into dry NW flow on Saturday. As is typical for May there will be moderate to strong onshore flow to the east through the period. Many of the csts and some lower vlys will likely have night through morning low clouds and fog. Hgts are not too high so the fog will likely not be dense. Aside from the low clouds skies should be mostly clear. The strong push to the east will bring moderate seabreezes and gusty afternoon winds in the Antelope VLy.
Look for massive warming Wednesday as sunny skies and rapidly rising hgts combine to bring 3 to 6 degrees of warming across the csts; 5 to 10 degrees across the vlys and 10 to 15 locally 18 degrees across the mtns and far interior. Thursday will see continued warming with most areas picking up an extra 4 to 8 degrees. Another 1 to 3 degree added to the max temps on Friday will bring the beaches up to the lower 70s with mid 70s to lower 80s further inland. The vlys will be in the mid 80s to lower 90s. 90s will be common across the far interior and lower mtn elevations. Cstl temps will be about 6 degrees over normal and the rest of the area will mostly be 8 to 12 degrees above average. Continued warm over the weekend with little day to day change in the temps.
03/1756z.
At 17Z at KLAX, the marine layer was 4200 feet with an inversion to 6200 feet at 9C.
High confidence TAFs for KWJF and KPMD.
Moderate confidence in increasing cig heights through the period with a rapidly deepening moist layer. However, there is a 10-20 percent chance of -dz/-shra and at least brief MVFR cigs/vsbys at pretty much anytime through the TAF period.
KLAX, Moderate confidence in TAF. There there is a 30 percent chc of SCT conds 21Z-01Z. No significant easterly wind component is expected.
KBUR, Moderate confidence in TAF. There is a 30 percent chc of SCT conds aft 20Z.
03/957 AM.
Increasing risk of SCA conditions for the entire Santa Barbara Channel, especially central and eastern portions this evening with a 40 percent chance of a SCA being issued by early this afternoon for this time frame.
There is a 30-60% chance of SCA level W to NW winds across the waters south of Point Conception Tuesday afternoon and evening. SCA conditions are most likely near the Channel Islands and across the Santa Barbara Channel.
Also, there is a 30% chance for SCA winds across the nearshore waters along the Central Coast during the aforementioned timeframe.
From Wednesday through Friday, winds are expected to increase each day across the Outer Waters and along the Central coast. SCA winds are possible on Wednesday, and likely Thursday into Friday. These winds could impact western portion of SB Channel by then.
Ca, NONE. PZ, NONE.
