22/106 PM.
Minimal changes expected through the weekend with above normal temperatures. Patchy night and morning low clouds and fog will be confined to coastal areas, mostly north of Point Conception. Additional warming is expected next week with periods of extreme heat in some areas, especially starting Tuesday.
(tdy-Tue), 22/221 PM.
The heat is on. It looks to be a very hot week across southwest California, especially Tuesday and beyond as high pressure aloft builds in from the east onshore gradients start to relax and possibly even turn lightly offshore. Temperatures today are similar or slightly cooler than the last couple days but models are indicating weakening onshore flow this week, especially starting Tuesday while at the same time heights and thicknesses rise due to high pressure building from the heat. In addition, overnight lows will be warming up as well which will limit the amount of recovery. For these reasons a heat advisory has been issued for all non-desert areas south of Pt Conception Sunday through Tuesday morning.
At that point models indicate the potential for light to locally moderate offshore flow. There is still quite a bit of uncertainty with this part of the equation which is why the heat hazards turn into Extreme Heat Watches Tuesday through Friday. If gradients end up being more onshore then most areas will likely just remain under heat advisories. Current projections indicate around a 30% chance of 110 or higher in the San Fernando Valley and also a 40% chance of 100 or higher in Downtown LA.
Winds in most areas are expected relatively light, under 20mph, however there will be some evening sundowners starting Monday evening.
For areas north of Pt Conception, temps will be warming there as well but the hottest temps will hold off until Tue or Wed.
(Wed-Sat), 22/219 PM.
The extreme heat is expected to continue through the week peaking late in the week. As high pressure continues to build the warm air will start to push north along the Central Coast and will likely need to be issuing additional heat advisories and/or warnings for some or all of the area by Wednesday. Projections show around a 10% chance of 100 degrees in SLO Wed-Fri and a 50-70% chance of highs of 105-110 across interior SLO. In addition, hot Sundowners will be peaking Tuesday and Wednesday evenings across the Santa Ynez Range with strong gusts and temperatures in the 90s and lower 100s likely.
Farther south the heat will just get worse later next week with some coastal valleys as high as 113 by Friday and a 20-40% chance of highs 100 or higher in Downtown LA and Camarillo.
Some cooling expected to start next Saturday but still at least 6-12 degrees above normal.
22/1754z.
At 1640Z at KLAX, the marine layer was 600 feet deep. The top of the inversion was at 3100 feet with a temperature of 28 C.
High confidence in most of the 18Z TAFs with VFR conds for nearly all airfields.
Moderate to high confidence for the TAF at KSBP as there is a 20%-30% chance of IFR cigs/vsbys about 11Z-16Z Sun morning. Otherwise VFR conds are expected.
Low to moderate confidence for the TAF at KSMX due to uncertainties with timing of low clouds and IFR/LIFR conds about 06Z-18Z Sun. Timing could be off +/- an hour or two.
KLAX, Generally hi confidence in the 18Z TAF with VFR conds expected. However, there is a 20% chance of IFR conds between 13Z-16Z Sun morning. If CIGs occur, the timing could be off by 2 hours. No significant east wind component is expected.
KBUR, High confidence in the 18Z TAF with VFR conds expected.
22/103 PM.
Moderate to high confidence in Small Craft Advisory (SCA) level winds (20-30 knots) across the Outer Waters at least through Monday night, most prevalent south and west of Point Sal. This may need to be extended through mid week and expanded to all waters again later in the week. SCA winds gusts are also expected across the nearshore waters along the Central Coast this afternoon and evening, then there is a moderate chance for more widespread wind gusts reaching 25 knots during the afternoon and evening hours starting Tuesday and continuing thru Thursday.
Gusts of 20-25 knots should reach the western half of the Santa Barbara Channel each afternoon/evening starting Monday and continue thru Thursday. Otherwise widespread SCA conds are not expected for the southern inner waters through the period.
Ca, Extreme Heat Watch in effect from Tuesday morning through Friday evening for zones 38-87-88-349>358-362-366>376-378>383-548. (See LAXNPWLOX). Heat Advisory in effect from 10 AM Sunday to 10 AM PDT Tuesday for zones 87-88-349>358-362-366>376-378>380-548. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 2 AM PDT Sunday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 11 PM PDT Sunday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 4 AM PDT Tuesday for zones 673-676. (See LAXMWWLOX).
