textproduct: Los Angeles

SYNOPSIS

31/232 PM.

Dangerously hot temperatures are expected through this weekend, with potential for significant heat impacts. Some cooling is expected next week, but temperatures will remain above normal. Dangerous surf and rip currents are expected at many of the beaches this weekend, as a result of swells from a tropical cyclone located west of Mexico.

LONG TERM (TUE-FRI)

31/1255 PM.

The slow cooling trend will continue into next week, though temperatures will still be 3-6 degrees above normal. In addition, monsoon moisture may return by the middle part of next week, which will limit overnight cooling and keep humidities higher than normal. Therefore, heat hazards are likely at times next week.

AVIATION

01/0231Z.

At 0144Z at KLAX, the marine layer was around 1000 feet deep. The top of the inversion was 2600 feet with a temp of 29 degrees Celsius.

High confidence in VFR conds for KPRB, KBUR, KVNY, KPMD, KWJF.

Low confidence in TAFs for KSBP, KSMX and KSBA. There is a 20-30% chance of low clouds at these sites, and in this case 40% chance of LIFR conds overnight. Any cigs that form may be short- lived.

Low to moderate confidence in KOXR, KCMA and the LA Coastal sites. If low clouds affect these sites, IFR to LIFR conds are likely. The timing could be off by at least +/- 2 hours, and CIGs could form and dissipate at times between around 06Z to 15Z.

KLAX...Low to moderate confidence in the 00Z TAF. The timing of flight cat changes may be off +/- 2 hours from TAF, and lowest cigs may be off +/- 200 feet. No significant east wind component expected.

KBUR...High confidence in the 00Z TAF with VFR conds expected.

MARINE

31/828 PM.

For the Outer Waters, Small Craft Advisory (SCA) winds and seas will continue through this weekend before beginning to subside early next week. Winds will generally peak at around 30 knots but occasional gusts to 35 knots will be possible, mainly during the evening hours.

For the Inner Waters north of Point Sal, there is an 60-80% chance of SCA winds during the afternoon/evening hours, decreasing to a 30% chance starting Sunday.

For the Inner Waters south of Point Conception, there is a 40% chance of SCA winds each afternoon and evening through this weekend over the western portion of the Santa Barbara Channel.

Seas of 7-10 feet will impact the outer waters into this weekend, due to a combination of long-period southerly swell from a distant tropical cyclone and shorter- period northwesterly swell/wind- waves caused by the moderate to locally strong NW winds. As a result, steep, hazardous seas will be common, especially over the outer waters, extending to nearshore waters off the Central Coast.

BEACHES

31/829 PM.

Distant Tropical Cyclone Genevieve is generating S-SE swells that will continue to affect the beaches into this weekend. A High Surf Advisory remains in effect for the south facing beaches of LA County, with a Beach Hazards Statement for the Ventura Coast northward to the Central Coast. In LA County, in spite of lower wave heights, south facing beaches are still seeing frequent, strong, and hazardous rip currents. For Ventura County (and SBA South Coast) surf heights are low enough and rip currents mainly moderate. Further north, strong rip currents are likely along the south to southwest facing beaches of the Central Coast.

Use extra caution if you are at the beach, and be sure to ask lifeguards if and where it is safe to swim.

Please reference the Coastal Hazard Message for details on High Surf and Coastal Flood Advisories, as well as Beach Hazards Statements. Dangerous rip currents will be of particular concern this weekend.

FIRE WEATHER

31/833 PM.

Today through at least Sunday, widespread elevated to brief critical conditions will be common away from immediate coasts due to very hot, dry, and locally breezy conditions with an increased risk for large plume dominated fire behavior and rapid fire growth due to deep mixing heights. For today and Sunday, mixing heights of 10,000 to 14,000 feet are expected across the interior, peaking on Saturday at 12,000 to 16,000 feet. If any fire ignitions occur across the interior, these deeper mixing heights allow for large vertical plume growth, especially in the mountains and foothills, where Live Fuel moisture levels are approaching critical levels.

Other factors that will add to the fire weather risk across the interior today through Sunday, will be locally breezy southwest to north winds 10 to 20 mph with gusts 20 to 30 mph, which could increase by another 5 mph by Sunday afternoon/evening as onshore flow increases, as well as widespread and long duration single digit humidities. As a result, expecting at least a few hours of wind/RH overlap to reach brief critical fire weather conditions across many interior areas through the weekend, and a few isolated mountain and Antelope Valley foothill locations could reach 6+ hour durations of wind/RH overlap. In addition, there will be very poor to poor overnight humidity recoveries, especially in the mountains and foothills where some locations may continue to have humidities in the teens.

Very warm and dry conditions will also impact southwest Santa Barbara County, with weak Sundowner winds likely (with gusts 25 to 40 mph from Gaviota to San Marcos Pass) this evening and Saturday evening, with humidities falling to between 15 and 25 percent. Very warm and dry conditions will likely persist much of next week across the interior, likely leading to more elevated to brief critical fire weather conditions.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Extreme Heat Warning in effect until 8 PM PDT Sunday for zones 38-88-343>345-351>353-355>358-368>376-378-379-381>383-548. (See LAXNPWLOX). Coastal Flood Advisory in effect until 3 AM PDT Saturday for zones 87-354-362-366. (See LAXCFWLOX). High Surf Advisory in effect until 5 PM PDT Saturday for zones 87-362-366. (See LAXCFWLOX). Beach Hazards Statement in effect through Saturday afternoon for zones 340-346-349-350-354-356. (See LAXCFWLOX). Heat Advisory in effect until 8 PM PDT Sunday for zones 341-342-347>350-354-362-366-367-377-380. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 3 AM PDT Saturday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 5 PM PDT Saturday for zones 670-673-676. (See LAXMWWLOX).