28/801 PM.
Quiet weather with near seasonal temperatures will prevail this week. Breezy west to northwest winds will occur across portions of the area at times. A late season rain is possible early next week.
(Tue-Fri), 28/952 PM.
***UPDATE***
Temperatures warmed well under sunny skies and rising heights, with widespread highs in the upper 60s to 70s. Looking at a slight warming trend through the week, with sub-advisory level offshore winds developing Wednesday and Thursday mornings, and a late return of afternoon onshore winds. An upper level low is forecast to pass to the south of the region Wednesday into Thursday, before another ridge of high pressure will bring more noticeable warming Friday. There is just a slight chance for some isolated showers associated with this low, generally from Ventura County and southward. Current high resolution guidance suggests Thursday now has the best chance, focused on the southern mountains and southern coastal waters.
Tonight, breezy north winds have developed over the western Santa Ynez Range along with some gusty west winds along the I-14 Corridor. Winds are expected to remain below advisory levels, and a few areas of low clouds and patchy fog are possible near Point Conception and for southern portions of the LA Basin. Current forecast looks on track.
***From Previous Discussion***
Gradient driven (lack of cold air advection) offshore trends and full sunshine for most will provide a nice warm up of 5-10 degrees away from the coast with highs generally in the 70s.
For Wednesday southwest California will be under a col area between a large trof over the Great Basin and an upper well to the SW of Pt Conception into. There will be enough of an onshore push to bring low clouds to the LA south coast and the SBA county west coast in the morning. A few more degrees of warming is forecast although the stronger onshore push in the afternoon might result in less warming across the csts and lower vlys. There is a small chance of a few afternoon showers focused over the mountains of Los Angeles and Ventura Counties.
The upper low to the SW will sweep harmlessly to the SE and pass south of San Diego Thursday. The SLO to LA area will see rising hgts and weak offshore flow. The offshore flow will likely not be enough to prevent low clouds from developing across LA south coast and the SBA county west coast in the early morning. Max temps will respond nicely with 1 to 3 degrees of warming across the csts vlys (xcp for the Central Cst where the sea breeze will cool the area by a degree or two). The far interior will warm by 4 to 6 degrees. A few degrees of additional warming is likely Friday.
There will be gusty winds across the Antelope Vly, the I-5 corridor and the western portion of the SBA south coast each late afternoon and evening strongest Thursday night.
(Sat-Tue), 28/957 AM.
Weak ridging with ~575 dam hgts will dominate the weather Saturday. There will be moderate onshore flow. The onshore flow could lead to some night through morning low clouds and fog across the csts and lower vlys and b. Limit the amount of warming created by the ridge esp along the csts. Look for 2 to 4 degrees of warming on Friday with little change on Saturday. Max temps everywhere, save for the beaches, will end up 2 to 4 degrees above normal.
There is much better agreement this morning between the mdls (deterministic, AI and ensemble) for the Sunday and early next week forecast.
A very large (for May) 558 dam upper low will move south about 100 miles west of the Bay Area on Sunday. SW flow will set up over the area. It will be dry, but there will be plenty of mid and high clouds and likely a grip of morning low clouds. Max temps will cool 3 to 6 degrees.
The low will move to the east starting Sunday night. It will bring a chance of rain to the area Monday and/or Tuesday. Right now amounts do not look like they will be too great. Although one caveat is that if the storm moves directly overhead (about a 20 percent chance) pockets of heavier showers or even a few thunderstorms would become possible. Max temps will nose dive 4 to 8 locally 10 degrees and will end up only in the mid 60s to lower 70s across the csts/vlys or 3 to 6 locally 8 degrees blo normal.
29/0206z.
At 00Z at KLAX, the marine layer was about 1400 feet deep. The top of the inversion was 4000 feet with a temperature of 12 degrees C.
Overall high confidence in the TAFs away from the coasts. Moderate confidence in coastal TAFs, and there is about a 30-40% chance for cigs at KSMX, KSMO and KLGB.
KLAX, High confidence in TAF through 06Z then lower confidence due to the potential for low clouds. No significant east wind component is expected.
KBUR, High confidence in TAF.
28/810 PM.
Moderate confidence in Small Craft Advisory (SCA) W-NW winds across the outer waters and nearshore along the Central Coast tonight. Moderate to high confidence that the SCA level winds will persist through late Thursday night, and possibly into Friday, especially over the northern outer waters. Moderate confidence that conds will remain near but below SCA levels through Saturday, with winds likely decreasing further on Sunday. Along the Central Coast, SCA winds are likely each afternoon and evening period through Thursday, followed by lighter winds through the weekend.
For the Santa Barbara Channel, SCA winds are possible in the afternoon and evening Wednesday (30-40% chance) over the western portion of the channel. There is a higher chance of SCA winds Thursday afternoon and night, followed by lighter winds through the weekend.
Otherwise, typical winds expected elsewhere which includes gusty (but under SCA winds) nearshore each afternoon.
High confidence in swell remaining rather small through Thursday, but choppy seas will increase with the winds each afternoon and night. Thursday night into the week seas will build, potentially reaching 10 feet over the northern outer waters by Saturday.
CC
Ca, NONE. PZ, Small Craft Advisory in effect until 3 AM PDT Wednesday for zones 670-673-676. (See LAXMWWLOX).
