19/245 AM.
Night through morning marine layer clouds will be confined to the coastal areas, mostly north of Pt Conception, through much of this week. Warmer and drier conditions are expected away from the immediate coast, with the heat peaking today and Thursday, when moderate heat risk is expected in warmest locations.
(tdy-Fri), 19/245 AM.
Today and Thursday will be the warmest days of the next 7 with heat hazards continuing for may vlys areas as well as the lower mtn elevations. 596 dam hgts (6 dam above normal), weaker than normal onshore flow and a greatly reduced marine layer will bring max temps of 95 to 105 degrees to many areas away from the csts. Even the interior coastal sections (such as DTLA) will have max temps in the lower 90s. Heat Advisories are in effect for the LA vlys and all of the lower mtn elevations. People outside of the advisory area still need to take precautions from the heat which will be 4 to 8 degrees above normal.
There will be some cooling on Friday, but perhaps not enough to eliminate the need for heat products esp considering that the humidities will be rising courtesy of the developing SE flow around the upper high which is fcst to move over the 4 corners area. This SE flow will also bring enough mid level moisture to create a 10 to 15 percent chc of convection over the mtns and Antelope Vly in the afternoon.
Gusty north winds will affect southwest Santa Barbara County and the I-5 corridor near the Grapevine each evening and overnight. The gusts should almost all be below advisory levels with only a chance of isolated advisory level (45 mph) gusts in the Gaviota area.
(Sat-Tue), 19/245 AM.
All medium range models agree the the upper high will shift to the east in response to an upper low moving towards the coast. Hgts do not change that much and will hover around 594 dam. Gradients do not change too much through Monday, but offshore trends develop on Tuesday and Wednesday.
The weather will be pretty benign. There will be better low cloud coverage each night and morning.
Max temps will cool some with the best cooling across the Central Coast which is closest to the upper trof. Max temps will remain above normal for most areas south of Pt Conception, while below normal temps are slated for SLO and most of SBA counties.
The monsoon flow will weaken as the flow direction will not be optimal, but a 5 to 10 percent chc of mtn convection Sat and Sun.
19/0945z.
At 0822Z at KLAX, the marine layer was 700 feet deep. The top of the inversion was at 2100 feet with a temperature of 29 C.
High confidence in VFR TAFs for KPMD, KWJF, KPRB, KBUR, KVNY, and KSBA.
For KSBP & KSMX, timing of flight category changes could be +/- 90 minutes of forecast.
Fair confidence in TAFs for KOXR/KCMA/KSMO/KLAX with a 15 to 20 percent chc of IFR conds 12Z-16Z.
Moderate confidence in TAF for KLGB with a 30 percent chc of IFR cigs 11Z-16Z.
KLAX, Fair confidence in TAF. There is a 15 percent chance of BKN008 conds 13Z-16Z. No significant easterly wind component is expected.
KBUR, High confidence in VFR. No wind issues expected.
19/245 AM.
High confidence in Small Craft Advisory (SCA) winds across the Outer Waters through Sunday. Conditions may dip below criteria levels during the morning hours through Friday. Choppy seas are expected.
For the Inner Waters north of Point Sal, there is a 30-40% chance of SCA level winds through Thursday, and a 50-70% chance Friday into the weekend. Focused during the afternoon and evening hours.
For the Inner Waters south of Point Conception, SCA level winds are likely to reach into the western portion of the Santa Barbara Channel through the weekend. Focused during the afternoon and evening hours. Saturday and Sunday have the best chance (40%) for enough coverage to warrant the issuance of a SCA across the channel. Elsewhere, conditions should remain below SCA levels through at least Saturday.
Ca, Heat Advisory in effect until 8 PM PDT Thursday for zones 38-88-343>345-351-353-371>373-375-376-379-380-548. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 3 AM PDT early this morning for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Thursday for zones 670-673-676. (See LAXMWWLOX).
