13/1214 AM.
Warm but below normal temperatures will continue through Thursday, with coastal morning low clouds. Gusty Sundowner winds will continue through Monday. Temperatures look to increase towards the end of the week.
(tdy-Tue), 13/1058 AM.
***UPDATE***
Low clouds have cleared for all but southern portions of LA County into far southeast Ventura County. Low clouds may linger into the early afternoon for the Malibu area in particular, thanks in part to our weaker September Sun.
Wind hazards for later this afternoon to evening along the Central Coast to southwest Santa Barbara County look good. There is a 30 percent chance that a short-fused wind advisory will be needed for the I-5 corridor in the mountains late this afternoon through this evening.
***From Previous Discussion***
Steady lowering in day-to-day temperatures remains in play through Tuesday for several reasons. One, an upper-level trough of low pressure over the western United States will amplify each day. Two, surface pressure gradients will remain healthily onshore. Three, gusty Central Coast and Sundowner winds will peak over the weekend, then quickly weaken. These winds have limited the low clouds and fog development recently, but come Monday and Tuesday all indications are for a huge coastal eddy forming in their wake with rapid low cloud development and expansion. Would expect a few random reports of drizzle as well. All of this will boost the temperature drop. With all that stated, highs will still generally be in the mid 70s to mid 80s which is not cold, but not hot either and below normal by 5 or 10 degrees.
The aforementioned Sundowner winds will peak tonight in terms of strength and areal coverage. While the eastern Santa Ynez Range now looks fairly tame this morning, these winds should expand across the entire range tonight as the SBA-BFL gradient goes from near neutral to -4 millibars. Will leave the current Wind Advisories as is as a result, carrying us through tonight.
(Wed-Sat), 13/1234 AM.
Little change expected from Tuesday into Wednesday with below normal temperatures and lots of marine layer clouds. High pressure over the southeastern states will expand to the west Thursday through Saturday, but that expansion will be battling a small yet potent closed low spinning somewhere between San Fransisco and Portland. How those two features interact is still up in the air, with a fairly large spread in the ensemble projections in terms of the warmth of the air mass and the resulting high temperatures. A warming trend is very likely, but it could be only 5 degrees or it could be 15 degrees, or somewhere in between. The warmest scenario would knock on the door of some targeted Heat Advisories, but that is about a 20% chance at this point. The tropical Storm train off western Mexico looks to remain active through the week, but not seeing any significant moisture surge signals into California at this point.
13/1827z.
At 18Z over KLAX, the marine layer was 2000 feet deep. The top of the inversion was 3500 feet and 22 degrees Celsius.
High confidence in VFR conditions through at least Monday at KPRB, KSBA, KPMD, KWJF. Some low-end LLWS is possible at KSBA this evening 03-10Z with gusty north winds in the nearby hills.
For Tonight: LIFR/IFR ceilings possible at KSBP (10%) KSMX (30%). IFR/MVFR ceilings possible at KOXR (20%) KCMA (20%) KSMO (60%) KLAX (60%) KLGB (70%) KBUR (30%) KVNY (20%).
Moderate confidence in TAF timing (+/- 3 hours).
KLAX, 60% chance of IFR/MVFR cigs late tonight into Monday morning. Moderate confidence that any east winds will stay under 8 knots.
KBUR, 30% chance of IFR/MVFR cigs by Monday morning, with at least MVFR vsbys in haze likely.
13/736 AM.
Moderate confidence in current suite of Small Craft Advisories (SCA) and Gale Warnings (GLW). High confidence that winds will be strongest today and tonight of the current northwest push, Gale Force winds likely for the outer waters off the Central Coast. Upper-end SCA winds will reach into the nearshore waters along the Central coast and western Santa Barbara Channel today and tonight, with a 50% chance of low-end SCA winds for Monday afternoon and night. These winds will generate a building short- period fresh swell over all waters, peaking in the afternoon & evening hours.
High confidence in winds staying below SCA levels Tuesday through Wednesday or Thursday. Stronger than usual southeast winds are likely south of Point Conception however, especially on Tuesday morning. Local gusts to 20 knots possible between the islands.
Ca, Wind Advisory in effect until 8 PM PDT this evening for zones 340-341-346-347. (See LAXNPWLOX). Wind Advisory in effect until 6 AM PDT Monday for zones 349-351-352. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 9 PM PDT this evening for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 3 AM PDT Monday for zone 650. (See LAXMWWLOX). Gale Warning in effect until 6 AM PDT Monday for zones 670-673-676. (See LAXMWWLOX).
