.SHORT TERM (SAT-TUE)...07/943 PM.

***UPDATE***

Another extremely hot day across the area Saturday, though in most areas temperatures were 10-15 degrees cooler than Friday. And some areas were as much as 20 degrees cooler, and yet still in the mid to high 90s. Which speaks to just how anomalously hot Friday was.
Sunday is going to be another interesting day temperature-wise across the area as there are some conflicting factors. Pressure gradients are trending back offshore again, much like they did prior to Friday's super hot day. However, the significant cooling from today still lingers this evening and Sunday may be starting off at a much cooler temperature than Friday. There's also a rapidly advancing stratus layer moving down the Central Coast that may be a factor, though possibly just for coastal areas north of Pt Conception.

Have made some minor adjustments to highs Sunday mainly to account for the actual highs today and then adding a 1-3 degree bump across LA/Ventura Counties due to the expected 1mb offshore trend. There's maybe a 10-20% chance temperatures soar back to Friday's levels, but probably a higher chance that temperatures end up very close to Saturday's levels factoring in the cooling from today. Either way, it's still going to very hot, at least 10-15 degrees above normal and in some areas as much as 20-25 degrees above normal. Please continue to avoid strenuous outdoor activities at any time of day and remember that often this time of year the mountains are just as warm if not warmer than the lower elevations.

***From Previous Discussion***

Synoptically, there is a large 592 dam upper level High centered just west of the four corners area bring the heat to the area, as well as transporting in some moisture that has already formed clouds over the eastern San Gabriel Mountains. The high will weaken slightly on Sunday, allowing for a few degrees of cooling, but maintain its favorable position for another afternoon of mountain showers. A little more weakening is expected on Monday, as well as the feature moving to the east, reducing the chances of afternoon rain. By Tuesday the High will be far enough east that a trough can move southward along the California coast and really drop temperatures, ending this heat wave. While our area will remain in the trough through the extended, the rain associated with the trough should stay in northern California.

Saturday is another hot day, with downtown Los Angeles 98 degrees, 104 degrees in Palmdale, 100 in Paso Robles, and much higher than normal temperatures nearly everywhere in the area. The gradient has just switched to weakly onshore and starting to see some cooler onshore wind along the coast in the last hour. While temperatures will very likely be slightly cooler today relative to Friday's highs, a very hot air mass remains with temperatures ranging between 15 and 25 degrees above normal for this time of year. Seeing active convective activity to our south and east as the High is bring moisture into the area. Clouds have already formed over the eastern San Gabriels and there is a good deal of lightning near Lake Arrowhead. As it is so hot and dry in the layer below the storms, there is a chance that any lightning from the storms will be hitting dry ground. DCAPE values suggest a gusty outflow wind threat, which could make gusty and erratic winds with any storms that develop, making initial attack of any potential fire starts difficult. and a Red Flag Warning is in place.

The mid-level clouds will remain in place tonight and again inhibit radiative cooling during the overnight hours. A tight northerly pressure gradient will reform tonight and bring gusty advisory- level Sundowner winds to southwestern Santa Barbara County late this afternoon and evening. A wind advisory is in effect between 4 pm and 3 am Sunday morning. Isolated gusts to 50 mph cannot be ruled out in the favored locations.

Sunday will be quite similar to Saturday, if slightly cooler. HRRR is solutions show a broader area with convection chances - spanning from our eastern San Gabriels to the Ventura County mountains including the Santa Susannas. Gusty Sundowner winds will likely linger in the forecast for Sunday evening.

By Monday the High will begin to move to the east and essentially remove the risk of afternoon thunderstorms. Heights fall slightly, but the clouds also should be less widespread, so not much of a change in temperature will result.

A big pattern change for the area by Tuesday as an upper level trough works its way down the California coast and heights could drop to as low as 586 dam. Precipitation associated with the trough and parent should stay well to our north.

.LONG TERM (WED-SAT)...07/153 PM.

By Wednesday, temperatures will cool to a near-normal 80 degrees in downtown Los Angeles, 90-degrees in Paso Robles and most points in between. NBM shows very little day-to-day variation in the temperature, with Thursday through Saturday all within a degree or two of each other. As the temperatures drop, low clouds and morning fog will gradually return to coastal locations, and by Thursday may be making it into some interior locations along the Central Coast. In the extended outlook, the NBM shows a very zonal pattern with only minor diurnal variation.

AVIATION
07/1744Z.

At 17Z at LAX, the marine inversion was around 500 ft deep. The top of the inversion was around 2500 feet with a temperature of 33 deg C.

Generally high confidence in the 18Z TAFs at most airfields with VFR conds expected thru the fcst period.

Moderate confidence for the 18Z TAF at KSMX. There is a 40%-50% chance low clouds and LIFR conds could affect the airfield about 10Z-16Z Sun. The onset and dissipation of any low clouds may be off +/- an hour or two. Otherwise, expect VFR conds thru the fcst period.

There is also a 10-20% chance of thunderstorms across the LA/ Ventura county mountains and Antelope Valley (including KPMD and KWJF) between 20Z and 03Z. Strong wind gusts locally over 40 knots are possible with any storms that develop.

KLAX...Hi confidence in the 18Z TAF with VFR conds expected through the forecast period. Any east wind component should remain under 5 kts.

KBUR...Hi confidence in the 18Z TAF with VFR conds expected through the forecast period.

MARINE
07/809 PM.

For the outer waters, generally high confidence in the current forecast. Small Craft Advisory (SCA) conds are expected to continue (70% chance) thru late tonight. There will likely be a lull in the wind very late tonight/Sun morning. SCA level winds are likely (60% chance) Sun afternoon into Sun night continuing for the central and southern outer waters zones (PZZ673/676) later Mon into Mon night. There is then a 40%-50% chance of SCA level winds for much of the outer waters for Tue through Thu night.

For the inner waters N of Pt. Sal, moderate to high confidence in the current forecast. SCA level winds are likely (60% chance)
afternoons and evenings Sun and Wed. There is a 30% chance of SCA winds during the afternoon/eve hours Mon and Thu. Otherwise, conds will be below SCA levels during the forecast period.

In the Santa Barbara Channel, moderate confidence overall in the current forecast. SCA level winds are possible (30% chance) in western portions and near the islands thru later tonight, with a 60% chance of these winds afternoon and evening hours Sun through Tue, and a 40% chance afternoons and evenings Wed and Thu.

In the southern inner waters, moderate to hi confidence in the current forecast. SCA conds are generally not expected thru Thu night. However, in northwestern sections, mainly from Anacapa Island to Malibu, there is a 30% chance of SCA level winds during the late afternoon/eve hours each day, except 50% chance Tue afternoon and evening.

Building seas associated with a long period west swell may approach SCA levels across the Outer Waters late Wed into early Thu.

Patchy dense fog will be possible during the night through morning hours through at least Mon, mainly across the outer waters to the inner waters N of Point Sal. Visibilities of one nautical mile or less can be expected.

LOX WATCHES/WARNINGS/ADVISORIES
CA...Excessive Heat Warning remains in effect until 8 PM PDT Monday for zones 38-88-351>353-356>358-362-366>380-548. (See LAXNPWLOX).
Heat Advisory remains in effect until 8 PM PDT Monday for zones 349-350-355. (See LAXNPWLOX).
Wind Advisory remains in effect until 3 AM PDT Sunday for zones 349-351-352. (See LAXNPWLOX).
Red Flag Warning in effect until 10 PM PDT this evening for zones 342-345-350-352-369-370. (See LAXRFWLOX).
Red Flag Warning in effect until 10 PM PDT Sunday for zones 349-351-353-375>383. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Monday for zones 670-676. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 AM PDT Tuesday for zone 673. (See LAXMWWLOX).