31/249 AM.
Temperatures will become dangerously hot in many areas Friday through this weekend, as the next heat wave arrives. Some cooling is expected next week, though temperatures will remain above normal. Dangerous surf conditions are expected at area beaches this week into this weekend, as a result of swells from a distant tropical cyclone located west of Mexico.
(tdy-Sun), 31/927 AM.
***UPDATE***
Heat is on track with 598 dm heights already, likely expanding to 599 or 600 dm later today. 24 hour warming trends of 5 to 10 degrees is common across coastal valleys with widespread mid 90s to around 105 likely for these areas today and upwards of 110 warmest interior valleys. No changes to heat hazards planned.
Please be heat aware today including frequent hydration, taking breaks, and avoid outdoor activities mid morning to mid evening when possible.
***From Previous Discussion***
Today and tomorrow are expected to be the hottest days in this heat wave as 500mb heights approach a rarely seen 600dam. If there is any good news in this scenario is that onshore gradients are expected to remain at least lightly onshore, allowing at least a light seabreeze to bring in some cooling ocean air inland by afternoon. Also a positive is that monsoon moisture is not expected to be a factor so it won't feel quite as sticky as last weekend. But even with those factors, temperatures will still be dangerously hot, especially away from the immediate coast, with highs 5-10 degrees above normal. It's highly recommended that any outdoor activities be completed before 9 and or after 7pm. And always have a source of hydration. And keep in mind, since sea surface temperatures are in the 70s south of Pt Conception, overnight lows will continue to much warmer than normal, mostly in the mid 60s to mid 70s. Saturday will be peak heat day in most areas with highs around 107 in the western San Fernando Valley, mid 90s downtown, and mid 80s to low 90s in the intermediate areas between the coast and the valleys.
Winds will mostly be under 15 mph, except some evening Sundowner winds across southwest Santa Barbara County up to 35 mph and up to 30 mph in the desert.
A large south swell from Tropical Cyclone Genevieve will further enhance large wave and potentially deadly rip currents for some area beaches.
(Mon-Thu), 31/324 AM.
The slow cooling trend will continue into next week, though temperatures will still be 3-6 degrees above normal. In addition, monsoon moisture is expected to return next week which will limit overnight cooling and keep humidities higher than normal. Therefore, heat hazards may continue into next week.
31/0239z.
At 0036Z at KLAX, the marine layer was 900 feet deep. The top of the inversion was 2900 feet with a temp of 28 degrees Celsius.
High confidence in VFR TAFs for KPRB, KBUR, KVNY, KPMD, KWJF. 10% chance for VLIFR-LIFR conds at KBUR/KVNY 10Z-16Z.
Low confidence in TAFs for KSBP and KSMX. 30% chance for VFR conds to prevail, but if cigs arrive, 40% chance for VLIFR conds also due to dense fog.
Moderate confidence in remaining TAFs, higher for LA County sites. Timing of flight cat changes may be off +/- 2 hours and flight cats may be off by 1 cat, but good confidence in low clouds overnight.
KLAX, Moderate confidence in TAF. 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 VFR TAF. There is a 10% chance for VLIFR to LIFR conds 10Z-16Z.
31/934 AM.
For the Outer Waters, Small Craft Advisory (SCA) winds and seas will occur through the remainder of this week into this weekend, before subsiding 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 80% chance for SCA winds each afternoon and evening through Saturday. 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 one-third of the Santa Barbara Channel.
Seas of 8-12 feet will impact the outer waters into this weekend, due to a long-period southerly swell from a distant tropical cyclone, combining with 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.
31/1016 AM.
Distant Tropical Cyclone Genevieve is generating long period S-SE swells that will affect the beaches for the remainder of this week into this weekend. A High Surf Advisory is in effect for the south facing beaches of LA and Ventura Counties through Saturday afternoon. Very strong, severe rip currents have been reported from some area beaches, with a risk of strong long-shore currents and sneaker waves. 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.
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 87-354-362-366. (See LAXCFWLOX). Beach Hazards Statement in effect through Saturday afternoon for zones 340-346-349-350-356. (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 Saturday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 5 AM PDT Monday for zones 670-673-676. (See LAXMWWLOX).
