textproduct: Los Angeles

SYNOPSIS

23/1112 PM.

High temperatures will remain above normal through Saturday. There will be some low clouds and fog each morning. Substantial cooling will arrive Sunday.

LONG TERM (SUN-WED)

23/128 PM.

A cooling trend will begin in earnest Sunday as a trough moves onshore over northern California. Confidence in the forecast beyond that remains murky as a tandem of two tropical systems jockey for position off the Baja coast. At this time there are exactly zero solutions that bring either of these systems to southern California. There are a couple of GEFS solutions that (out of many) that bring a much weakened Polo to the central part northern Baja, but the majority keep it over southern part of Baja. The track of Odalys is a little more uncertain but again all but one or two remain south of northern Baja. The message here is that the greatest threat to Southern California is again the beaches with periods of increasing south swells late Sunday and peaking Monday and Tuesday. Can't rule out a stray shower, however if the trough moves through as most of the models are suggesting then most of the moisture will be pushed south and east of LA County.

AVIATION

23/2335Z.

At 2311Z at KLAX, the marine layer was 1200 ft deep. The top of the inversion was at 2100 feet with a temperature of 29 C.

High confidence in VFR TAFs for KPRB, KPMD, and KWJF.

Low confidence in TAFs for KBUR and KVNY, as there is a 30% chance of LIFR-IFR cigs with best chances 12Z-17Z. Low confidence on min flight cat if cigs arrive.

Good confidence in cigs arriving tonight at remaining coastal sites except lower for KSBP (30% chance for no cigs). Lower confidence in min flight cats at all sites. Flight cats may be off by one. There is a 40% chance 1/4SM vis at KSMX and KSBP when cigs are present.

KLAX...Moderate confidence in TAF. Cigs may arrive as early as 03Z with cig heights most like 007-012. No significant east wind component expected.

KBUR...Low confidence in TAF after 10Z with a 30% chance for LIFR-IFR cigs 12Z-17Z. Low confidence on min cig height.

MARINE

23/843 PM.

Small Craft Advisory (SCA) will drop below advisory levels for all waters trough this afternoon. SCA level winds are likely to return this evening/night starting across far northern waters and locally near Point Conception. By Friday afternoon or evening, these winds will expand to cover the majority of outer waters and even reaching into the nearshore waters along Central Coast. Short- period steep, choppy seas most likely during this timeframe. Coverage and wind strength is likely to decrease some on Saturday with more focus near Point Conception. These SCA winds will expand in coverage again Sunday through early next week with increasing potential to reach into the Santa Barbara Channel.

BEACHES

23/214 PM.

The eastern pacific is currently active with Hurricane Polo, Hurricane Odalys, and tropical depression Fifteen-E south of Hawaii. This discussion will focus on the potential impacts from the SSE swell generated from Hurricane Polo.

Uncertainty is still rather high regarding the evolution (track, intensity) of Hurricane Polo. Current trends in guidance have shifted eastward with more solutions turning north and east making landfall in Baja California Sur.

With these current projections here are the latest thoughts: Expecting elevated SSE swells from Hurricane Polo with elevated surf, with potential impacts peaking Mon-Tues. Confidence is high in tide predictions near 7 ft Mon-Wed in the late morning hours. Low to moderate confidence for surf which is dependent on Polo's track which has not be ironed out yet.

The Swell is likely to have a more SE direction compared to Labor Day weekend event. Areas of most concern: Long beach (Peninsula and Belmont shore), Avalon, Malibu, and possibly Santa Barbara Harbor.

Scenario 1 (Mon-Tues): Coastal Flood Advisories (High Chance) Shallow flooding of sea water of low-lying walkways, parking lots, and roads. Significant beach erosion possible.

Scenario 2 (Mon-Tues): Coastal Flood Warnings (Low Chance) Flooding of sea water impacting structures, walkways, parking lots, and roads. Significant beach erosion expected.

LOX WATCHES/WARNINGS/ADVISORIES

CA...NONE. PZ...Small Craft Advisory in effect from 6 PM Thursday to 3 AM PDT Saturday for zones 670-673. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zone 673. (See LAXMWWLOX).