19/723 PM.
Near normal temperatures with night to morning low clouds and fog will continue into Monday. A long and dangerous heatwave is becoming more likely beginning as early as Tuesday and continuing through early next week.
(Sun-Wed), 19/800 PM.
***UPDATE***
A seasonally warm day today began with low clouds near the coast, burning off in most areas this afternoon, except for patchy low clouds along the Central Coast. Highs ranged from the mid 80s to the upper 90s to around 100 degrees away from the coast. Coastal locations ranged from 60s along the Central Coast to 70s to near 80s farther south.
Fairly quiet conditions are expected tonight and Monday. Low clouds are already moving over the Central Coast and are expected to follow suit over the remaining coastal areas overnight. The extent of low clouds will change little compared to last night, moving over the coastal basins, into the Santa Ynez and San Gabriel Valleys, but none of the other valleys should be affected.
Seasonably warm temperatures are expected Monday, with highs likely to change little, or warm a degree or two in some areas. Gusty onshore winds will again affect the interior passes and canyons and the Antelope Valley.
***From Previous Discussion***
There is a high risk (80 percent chance) for a long and dangerous heatwave beginning Tuesday and likely continuing through at least next weekend. NOW is the time to start planning ahead of the heat such as changing outdoor plans or finding places to stay cool and socialize this risk with friends and family. As with many heatwaves, there will also be an enhanced risk for large fires away from the coast. Please take care with fire ignition sources.
A ridge building in from the west and offshore trends will support a consistent warming trend starting in earnest Tuesday and continuing through at least Thursday. Widespread moderate Advisory level heat is likely (80 percent chance) for most areas by Wednesday. Daytime highs of 85-105 may become common away from the coast by Wednesday.
Tropical cyclone Elida will continue to weaken while sliding well to our west through Tuesday. Periods of mid to high clouds are expected near the Central Coast but may expand to other areas at times. There is a 5-10 percent chance of a shower or thunderstorm focused across this area and typical mountains of Los Angeles and Ventura Counties through Tuesday, lingering into Wednesday for Los Angeles County.
Otherwise night to morning low clouds may persist especially away from mid to high clouds through Wednesday. Dense fog may become more prevalent where low clouds persist by Wednesday morning.
Onshore winds will gradually weaken through the period, with locally enhanced northwest Sundowner winds ticking up to near advisory levels by Wednesday for southern Santa Barbara County.
(Thu-Sun), 19/131 PM.
The heat will likely continue Friday through the weekend, with continued warming very much in place by next weekend with a 40-50 percent chance of high warning level heat risk for many areas. Daytime highs of 85-105 will likely continue away from the immediate coast with a 40-50 percent chance of 90-110.
The building ridge may be positioned favorably to keep the monsoon door open with a 5-10 percent chance of showers/thunderstorms focused across interior areas, especially Los Angeles and Ventura Counties. The added humidity will add to the heat risk and assist in maintaining very warm overnight lows in the 70s to near 80 for at least interior valley and foothill locales.
Sundowner winds may near advisory levels again, especially Thursday evening. As they weaken an associated Catalina Eddy may provide a brief break from the heat near the coast Thursday or Friday, although much warmer than normal ocean temperatures and associated boost in humidities will limit the relief.
19/2353z.
At 2350Z at KLAX, the marine layer was 1400 ft deep. The top of the inversion was at 3200 ft with a max temperature of 25 C.
High confidence in VFR TAFs for KPMD, KWJF, and KPRB.
Moderate confidence in VFR TAFs for KBUR and KVNY. There is a 20% chance for LIFR to IFR conds 10Z-16Z.
Moderate to high confidence in remaining coastal TAFs. High clouds may disrupt marine layer formation tonight, but generally expected similar marine layer coverage compared to last night. Timing may be off +/- 3 hours and min cig height may be +/- 300 feet from TAF. 30% chance for VLIFR conds at KSMX overnight.
KLAX, Moderate confidence in TAF. Cigs may arrive as soon as 03Z. Cigs may remain at OVC010 or above when present. No significant east wind component expected.
KBUR, Moderate confidence in TAF. 20% chance for LIFR-IFR conds between 10Z and 16Z Mon. No wind issues expected.
19/726 PM.
Conditions are generally expected to remain below Small Craft Advisory (SCA) levels through Monday except for SCA level northwest wind gusts across the Outer Waters more than 20 NM from shore and near Point Conception through late tonight. Northwest winds will strengthen Tuesday, rising to SCA levels by Tuesday afternoon, and will likely continue through the rest of the week. Chances also increase for SCA level west to northwest winds in the western half of the Santa Barbara Channel during the same time.
A series of moderate period southerly swells will move through the waters through the week and likely beyond. These swells may impact south facing harbors, including the Port San Luis area.
19/724 PM.
Over the eastern Pacific, Tropical Storm Elida is forecast to continue to move to the north-northwest well off the California Coast. Another tropical disturbance is expected to develop in the same area and follow a slightly more westerly track along 20 N Latitude. Both systems will produce moderate period southerly swells. High Surf Advisories and Beach Hazards Statements have been issued across Southwest California and are in effect this evening through Tuesday night.
The secondary system on the heels of Elida as well as an incoming long period, southern hemisphere swell arriving later this week will contribute to continued and potentially more hazardous beach conditions late in the week and next weekend. Additional High Surf Advisories and/or Beach Hazards Statements will likely be needed later this week.
Looking beyond the forecast period, a series of tropical systems are forecast to develop off the coast of Mexico and move to the northwest, likely producing multiple rounds of southerly swells over the next couple of weeks.
Ca, High Surf Advisory in effect until 11 PM PDT Tuesday for zones 87-354-362-366. (See LAXCFWLOX). Beach Hazards Statement in effect through Tuesday afternoon for zones 340-346. (See LAXCFWLOX). PZ, Small Craft Advisory in effect until 3 AM PDT Monday for zones 673-676. (See LAXMWWLOX).
