textproduct: Los Angeles

SYNOPSIS

27/723 PM.

Hotter than normal conditions will continue for the foreseeable future. Slight cooling will take place through Thursday, with heat increasing again Friday through Sunday. The hot and humid conditions during the day and night will bring elevated risks of heat-related illness.

LONG TERM (FRI-MON)

27/143 PM.

Widespread MODERATE TO HIGH heat risk is very likely to return Friday into the weekend. Now is the time to start socializing this threat with your community and family and consider rescheduling activities that might but you or your loved ones at risk. Have a plan to stay cool, especially if work or other activities take you outside mid-morning to mid-evening hours or do not have access to air conditioning.

RECORD BREAKING or tying (for at least July since 1999) 500 mb heights of 598-600 dm is likely sometime Friday into Saturday with only modest weakening into early next week. A Heat Watch will eventually be needed to cover this very concerning period (especially Friday through Sunday) Widespread highs of 95-105 away from the coast with pockets of 105-115 in warmest coastal valleys to interior are likely during the peak of the heatwave Friday and Saturday. Highs 80-95 will be common coastal areas away from the beaches. Overnight lows in the 70s and 80s for many areas will increase risk for heat stress through prolonged exposure and limited ability for dwellings without air conditioning to cool overnight.

There is also an increased risk for large and dangerous fires due to the hot and unstable conditions with pockets of gusty winds, perhaps, especially southwest Santa Barbara County and the I-5 corridor in the mountains into the weekend.

Night to morning low clouds will diminish or disappear during this time, although weakened onshore focused to the east will somewhat limit the heat nearest the coast. However, well above normal water temperatures will somewhat maintain the humid muggy feeling near the coast, decreasing the body's ability to cool through sweating.

AVIATION

28/0617Z.

At 0522Z at KLAX, the marine layer was 900 ft deep. The top of the inversion was near 1800 ft with a temperature of 26 C.

High confidence in TAFs for KBUR, KVNY, KPMD, KWJF, and KPRB.

Moderate confidence in TAFs for KLGB, KLAX, KSMO, KSBP, and KSMX where the arrival and departure times of CIGs could be off by +/- 2 hours. Min CIG heights may be off by +/- 200 feet, with a 20% chance for VLIFR conds at KSMX/KSBP. There is a 30-40% chance cigs fail to reach KLGB, KLAX, and KSMO.

Moderate confidence in TAFs for KOXR and KCMA with a 30 percent chc of IFR/LIFR cig/vis 12Z-17Z.

KLAX...Moderate confidence in TAF. Cigs could arrive as early as 09Z and as late as 14Z. VFR conds could arrive as early as 15Z or as late as 17Z. High confidence in any east winds staying under 7 knots.

KBUR...High confidence in CAVU TAF.

MARINE

27/949 PM.

Good confidence in a prolonged period of gusty northwest winds across the coastal waters through this week, except for nearshore south of Point Conception (including eastern Santa Barbara Channel and the waters adjacent to the Los Angeles and Orange County coasts). Small Craft Advisory (SCA) conditions will be fairly persistent, with localized gale force gusts possible this afternoon and evening over the outer waters.

Nearshore south of Point Conception, marginal SCA level winds (20-25 knots) will become common across the western half of the Santa Barbara Channel each afternoon and evening with low chances of extending into eastern portions of the Channel. The southern nearshore waters are expected to see winds below 20 knots.

Seas are expected to hover near 8-10 feet across the waters away from the coasts much of the week. A southerly swell from Hurricane Genevieve will send a southerly swell into the waters tonight into tomorrow, which will continue into the weekend. This south swell may impact south facing harbors, including Port San Luis.

BEACHES

27/202 PM.

An extended period of a combination of moderate to long period southerly swells will continue through this week and into next weekend. A long 17-20 second period SSW Southern Hemisphere swell will continue to impact our area through mid week. Then Category 5 Hurricane Genevieve will send another southerly swell to SoCal Tuesday.

A Beach Hazards Statement is in effect through Wednesday (except through Saturday along the Central Coast) due to the increased risk of dangerous rip currents and elevated surf. There have been numerous ocean rescues reported.

A High Surf Advisory has been issued for Wednesday evening through Saturday evening for the incoming southerly swell due to Hurricane Genevieve, particularly for south facing beaches exposed to southerly swell (such as from Manhattan Beach to Port Hueneme along the Malibu Coast, and from Long Beach to the Palos Verdes Peninsula). This swell will peak around 3-5 feet at 12-15 seconds from 160-180 degrees.

Additionally, a Coastal Flood Advisory has been issued for Wednesday evening through Friday evening for the Ventura and Los Angeles County Coasts. High tides of 6.2-7.0 feet will peak in the evening hours. In conjunction with the highest expected surf from the Hurricane Genevieve southerly swell, the best potential for minor coastal flooding impacts is expected Wednesday and Thursday evening. Generally minor impacts are expected, such as pooling of seawater over low lying coastal areas in susceptible areas.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Beach Hazards Statement in effect through Wednesday afternoon for zones 87-354-362-366. (See LAXCFWLOX). Coastal Flood Advisory in effect from 5 PM Wednesday to 3 AM PDT Saturday for zones 87-354-362-366. (See LAXCFWLOX). High Surf Advisory in effect from 5 PM Wednesday to 5 PM PDT Saturday for zones 87-354-362-366. (See LAXCFWLOX). Beach Hazards Statement in effect through Saturday afternoon for zones 340-346. (See LAXCFWLOX). Wind Advisory in effect until 3 AM PDT Tuesday for zones 349-351. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for zone 645. (See LAXMWWLOX). Gale Warning in effect until 3 AM PDT Tuesday for zones 670-673-676. (See LAXMWWLOX).