textproduct: Los Angeles

SYNOPSIS

08/944 PM.

Above-normal temperatures will persist today, before a weak storm system crosses the region later Tuesday through Wednesday. Light to moderate rain is expected, mainly Tuesday evening through early Wednesday, with gusty southerly winds over the higher terrain, especially Tuesday night. Temperatures will cool during the middle of this week, followed by a gradual warming trend for late week into the weekend. For the following week, multiple rounds of precipitation and much cooler conditions are increasingly likely.

LONG TERM (THU-SUN)

08/230 PM.

A reinforcing and diffuse cyclonic-flow perturbation behind the departing vort max will anchor mid/upper troughing over the local area on Thursday, keeping seasonably cool conditions in place. However, stronger ascent should be well east of the area by Thursday while mostly dry conditions prevail. Thereafter, a midlevel ridge is forecast to quickly build over the local area, with high temperatures rebounding into the upper 60s and lower 70s over the coastal valleys and L.A. Basin by Friday and Saturday under mostly sunny skies.

Thereafter by late next weekend and into the extended outlook beyond next weekend, medium-range model guidance is continuing to suggest increasing probabilities for a much cooler pattern featuring multiple rounds of precipitation. This would be in conjunction with a longwave, high-amplitude trough developing offshore and along the Pacific Coast vicinity. Uncertainty inherent to the forecast regarding weather conditions and related impacts is significant. However, in general, numerical models are offering above-average consensus regarding the longwave pattern over the local area for this distant of a time range. While the details are highly uncertain, there is growing concern for precipitation and cool-temperature impacts in the extended outlook starting next Sunday and continuing through the following week. Interests across the local area are encouraged to monitor the latest information from the National Weather Service in Los Angeles/Oxnard, California, as forecast details become refined over the coming days.

AVIATION

09/0554Z.

At 0450Z at KLAX, there was no marine layer. There was a sfc based inversion with a top of 1000 ft and a temp of 22 C.

High confidence in TAFs, except KPRB (40 percent chc of no cigs) and KLGB (30 percent chc of LIFR conds 12Z-16Z)

KLAX...High confidence in TAF. Any east wind component will be under 7 kt.

KBUR...High confidence in TAF.

MARINE

08/751 PM.

Across the Outer Waters and nearshore waters along the Central Coast, hazardous ocean conditions will be common much of the time through Wednesday, and again late Thursday through the weekend. SCA winds are expected to continue into Monday afternoon, and then Gale Force southwesterly winds are likely mid- morning Tuesday into Tuesday night, especially for the waters north of Point Conception. Small Craft Advisory (SCA) seas will be likely Tuesday through Wednesay, followed by periods of SCA winds and seas late Thursday into the weekend.

For the Santa Barbara Channel and southern inner waters, hazardous conditions are likely Tuesday afternoon through Wednesay night, with SCA level winds (especially in the channel) and choppy steep seas. SCA conditions will be possible across the Santa Barbara Channel Thursday night through Friday night.

BEACHES

08/743 PM.

Elevated surf will likely continue through this coming week. High surf will affect the Ventura County beaches through Wednesday. The swell will primarily be out of the west, but will briefly become more southwest late Tuesday through Wednesday. During this time period, typically more sheltered south to southwest-facing beaches and harbors will see elevated-to-high surf conditions. Friday into the weekend, another large northwest-to-west swell will bring even higher surf conditions to at least the Central Coast with the potential to extend south. Please see SRFLOX and the CFWLOX for additional details.

LOX WATCHES/WARNINGS/ADVISORIES

CA...High Surf Advisory in effect until 9 PM PST Wednesday for zone 354. (See LAXCFWLOX). PZ...Small Craft Advisory in effect until 9 PM PST Monday for zones 645-670-673-676. (See LAXMWWLOX).