textproduct: Los Angeles

SYNOPSIS

01/851 AM.

Hot temperatures are expected through this weekend, with a high risk for heat illness especially inland of the coast. Temperatures will lower next week, but it will remain very warm and likely 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)

01/316 AM.

The slow cooling trend will continue through Monday then basically flat lines the rest of next week at roughly 1-5 degrees above normal and minimal day to day temperature variations, placing us squarely in the dog days of summer. If there's any good news in this it's that monsoon moisture is expected to remain out of the area through mid week. Unfortunately there are strong signals for increasing moisture by Thursday and Friday next week with still very strong high pressure aloft, so humidities are likely to be a factor again.

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

01/844 AM.

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 through 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.

Dense fog will affect some of the coastal waters each night and morning going forward.

FIRE WEATHER

01/941 AM.

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, mixing heights of 12,000 to 16,000 feet are expected across the interior, and 10,000 to 14,000 feet on Sunday. If any fire ignitions occur across the interior, these deeper mixing heights will 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 Red Flag durations of wind/RH overlap. Since the necessary Red Flag duration of 6+ hours is expected to be isolated, no Red Flag Warning is expected to be issued for today. 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.

Warm and dry conditions will also impact southwest Santa Barbara County, with weak Sundowner winds likely (with gusts 25 to 35 mph from Gaviota to San Marcos Pass) this evening, with humidities falling to between 20 and 30 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). High Surf Advisory in effect until 5 PM PDT this afternoon for zones 87-362-366. (See LAXCFWLOX). Beach Hazards Statement in effect until 5 PM PDT this 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 from 3 PM this afternoon to 3 AM PDT Sunday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PDT Sunday for zones 670-673-676. (See LAXMWWLOX).