08/831 PM.
Much cooler conditions are expected on Monday as a coastal eddy brings southeast flow to the area along with coastal low clouds and fog. The cooling trend will continue into Tuesday, with another warm and expected to start on Wednesday, lasting through at least Friday and possibly into next week.
(Sun-Wed), 08/842 PM.
***UPDATE***
The gusty offshore winds continue to subside this evening, with only a few windy spots left at higher elevations. These winds allowed for significant warming over the region today, and high temperatures climbed into the 80s to near 90 for the Los Angeles and Ventura coasts and valleys. Somewhat cooler highs occurred up north, with 70s and low 80s common.
These offshore winds will shut off as the low to the south weakens and tracks southeast. However, guidance is consistent in developing an eddy circulation tonight, which should bring some breezy southeasterly winds to the coasts from Point Conception southward. Marine layer clouds have already developed off the Central Coast, and should reach the coasts by the early morning hours. There is also potential for marine layer clouds to develop and move into southwestern LA County, however lower confidence in this as clouds have not yet developed. The current forecast looks on track with cooler weather expected early on in the week.
***From Previous Discussion***
Offshore winds have begun to subside this afternoon and will allow the Wind Advisory to expire on time at 3 pm. Breezy east winds will transition south to southeast into Monday morning with a southerly surge expected to bring morning low clouds and fog to the coast and significant cooling to all but the far interior areas. The same low pressure system that has supported the prolonged moderate to strong Santa Ana winds will spin back north into Monday and may bring mid to high level clouds to eastern LA County with any rain likely well to our east.
After daytime highs today well into the 80s and low 90s in warmer spots, we'll see highs only in the 70s into Monday. As such, the Heat Advisory will very likely be allowed to expire on time this evening. However, we are far from done with the heat as a prolonged period of widespread mid 80s to 90s will likely begin Thursday and may continue into next week. We'll see the very front end of the trends Wednesday as moderate offshore flow combined with a rapidly building ridge nosing in from the east to bump temperatures back into the 80s in warmer coastal valleys to interior. Breezy northwest to northeast winds are likely beginning Tuesday, possibly approaching advisory levels by Wednesday evening.
(Thu-Sun), 08/157 PM.
Max temps will be the main talking point of the three day stretch. Look for 5 to 10 degrees of warming (across the csts/vlys) both Wed and Thu with little change slated for Friday. Thu/Fri's max temps will be in the mid and upper 70s at the beaches, the 80s across the rest of the csts, and 90s for the vlys. These max temps are 15 to 25 degrees over normal.
The ridge will break down on Saturday and offshore flow from the north will weaken while the onshore push to the east will increase. Look for 3 to 6 degrees of cooling with max temps remaining well above normal with moderate heat impacts potentially continuing through the weekend and even into next week away from the coast.
Both AI-EC and AI-GFS are dry through the 23rd of the month.
09/0246z.
At 0100Z at KLAX, there was no marine layer or an inversion.
High confidence in VFR TAFs through this evening, then a chance for IFR-MVFR flight cats for KSMO, KLAX, and KLGB after 10Z. Low confidence in potential flight cats, especially early, where LIFR conds are possible. Moderate confidence in winds. A Catalina eddy will develop overnight, likely bringing SE winds to southern coastal/valley sites, possibly also including KSMX.
KLAX, High confidence in VFR conditions through this evening. Overnight, there is a 50% chance that cigs do not develop. Moderate confidence in an east wind component reaching 10 kt from 04Z-14Z. There is a 20% chance for brief winds gusting to 15 kt.
KBUR, High confidence in VFR conditions through the period. Moderate confidence in wind forecast as direction may be off by 30 degrees and gusts may be off by +/- 10 kt.
08/836 PM.
Santa Ana Winds have transitioned into northwest Small Craft Advisory (SCA) level winds across the waters near and southwest of Point Conception. A moderate Catalina Eddy will develop tonight, brining southeast to east winds of 15-20 knots with gusts to 25 knots to the waters south of Point Conception through tomorrow morning. The winds are expected to increase across the San Pedro Channel after midnight, then spreading north along the LA Coast and into the Santa Barbara Channel during the early morning hours.
Periods of SCA level northwest winds will then dominate the Outer Waters through the remainder of the week, with low chances of SCA level winds reaching the Inner Waters. Seas will also reach near 10 feet across the outer waters late Monday into Wednesday morning.
Ca, NONE. PZ, Small Craft Advisory in effect until 9 PM PDT this evening for zones 650-655. (See LAXMWWLOX). Small Craft Advisory in effect from 3 AM to noon PDT Monday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PDT Monday for zones 673-676. (See LAXMWWLOX).
