textproduct: Los Angeles

SYNOPSIS

12/201 AM.

Below normal temperatures prevail through at least Wednesday, with coastal morning clouds and gusty onshore winds. Warming likely to return towards the end of next week.

LONG TERM (TUE-FRI)

12/214 AM.

The Sundowner winds that peak over this weekend should weaken heading into Tuesday, which will allow the marine layer to expand and push deeper into the coastal valley areas. Otherwise, little change is expected from Monday through Wednesday with an upper level trough and moderate to strong onshore flow prevailing.

The consensus in models for Thursday through the end of next week is for warming, as high pressure builds in from the southeast and onshore flow weakens. The magnitude of that building high pressure and the offshore trends are still to be settled, which means the magnitude of the warming is uncertain. Temperatures pushing above normal look very likely, with a low but non-zero chance of Heat Hazard-level hotness. Peering down to the south, there are a couple of tropical systems that could provide some moisture, but the signal is weak at this point.

AVIATION

12/0906Z.

At 09Z at KLAX, the marine layer was 1500 ft deep. The top of the inversion was at 4000 ft with a temperature of 24 Celsius.

High confidence in VFR conditions through at least Sunday at KPMD and KWJF with seasonal winds.

Low clouds have already formed at KSBP KSMX KLGB KLAX. Chances for IFR/LIFR conditions at KPRB (10%) and KSBA (20%). Chances for MVFR/IFR conditions at KOXR (60%), KCMA (50%), KSMO (80%), KBUR (30%), KVNY (30%). Moderate confidence on TAF timing (+/- 3 hours). For Sunday clouds may be less prevalent, with chances for ceilings at KSBP (30%), KSMX (60%), KOXR (20%), KCMA (20%), KSMO (40%), KLAX (60%), KLGB (60%), KBUR (20%).

KLAX...MVFR ceilings will clear by 16-18Z. There is a 20% chance of brief MVFR ceilings 23-02Z). Ceilings likely later tonight into Sunday, but likely forming later.

KBUR...20-30% chance of brief BKN005-008 forming 12-16Z each morning through Sunday. High confidence in typical winds.

MARINE

12/201 AM.

High confidence in current suite of Small Craft Advisories (SCA) and Gale Warnings (GLW). Upgraded and expanded the Gale Watches to Gale Warnings for all the outer waters off the Central Coast. The warnings start later tonight and continue through Sunday Night, with Sunday afternoon and evening likely the strongest. Gale conditions may linger into Monday, but should be on the decrease.

Also issued SCA for the nearshore Central Coast and western Santa Barbara Channels for this afternoon and night, which will likely need to be issued again for Sunday afternoon and night. All of these winds will generate a building short-period fresh swell over all waters, peaking in the afternoon and evening hours.

There is a low but present risk for dense fog over the Central Coast waters today, with the risk decrease Sunday.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Wind Advisory in effect from 6 PM this evening to 6 AM PDT Monday for zones 349-351-352. (See LAXNPWLOX). PZ...Small Craft Advisory in effect from noon today to 9 PM PDT this evening for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 3 AM PDT Sunday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 6 PM PDT this evening for zones 670-673-676. (See LAXMWWLOX). Gale Warning in effect from 6 PM this evening to 6 AM PDT Monday for zones 670-673-676. (See LAXMWWLOX).