25/1152 PM.
Marine layer clouds with patchy fog will reoccur each night from the coasts to the coastal valleys, expanding into the valleys over the weekend. Temperatures will trend cooler, with below normal temperatures through Sunday. A slow warming trend will begin on Monday.
(tdy-Sun), 26/1207 AM.
The next three days (and beyond) will be dominated by a persistent night through late morning (or even afternoon) low cloud pattern. This pattern is the result of unusual cyclonic flow generated by a series of upper lows moving through the PACNW along with strong onshore flow (~9mb peak). Low clouds will arrive in the evenings and will be slow to clear with some clouds lingering into the afternoon across west facing nearshore areas.
Another effect of the strong onshore flow will be the gusty winds through the passes and canyons of LA County into the Antelope Valley. Look for persistent gusty winds, with isolated strong gusts, in the afternoon to evening hours through Sunday. As usual, the strongest winds will be over the interior, especially the Antelope Valley.
The combination of falling hgts, strong onshore flow and a deep persistent marine layer will bring cooling to most areas today through Sunday. Most cst and vly max temps will only be in the 70s through the period with mid to upper 60s across the beaches and a smattering of 80 or 81 degree readings in the warmest vly locations. These max temps are 3 to 6 degrees under normal for the csts and 6 to 12 degrees for the vlys.
(Mon-Thu), 26/159 AM.
Not much change in the June Gloom forecast for the end of the month and into July. A series of upper lows moving through the PACNW will keep cyclonic flow aloft through the period. Mdt to stg onshore flow will continue through the period xcp on Mon when there will be a noticable relaxation of the onshore gradinets.
Look for the night through morning low cloud pattern to continue although it should be a little less intense in coaverage and duration on Monday.
Look for 2 to 4 degrees of warming Monday with the weaker onshore flow, but all that warming will be lost Tuesday as the onshore flow strengthens again. Not much change on Wednesday and then a little more warming on Thursday as the upper level troffing is forecast to weaken. Max temps will remain many degrees under normal through the period.
26/0907z.
At 0832Z at KLAX, the marine layer was 1400 ft deep. The top of the inversion was at 4800 feet with a temperature of 19 C.
High confidence in VFR TAFs for desert airfields (KPMD & KWJF).
Moderate confidence in the remainder of the TAFs. Timing of flight cat changes could be off +/- 2 hours and CIG heights +/- 300 ft.
KLAX, Moderate confidence in TAF. OVC010 conds could arrive as early as 12Z. VFR transition could occur anytime between 20Z and 22Z. Good confidence that there will be no east wind component.
KBUR, Moderate confidence in TAF. There is a 30 percent chc of BKN004 OVC008 conds 12Z-15Z. There is a 25 percent chc of OVC008 conds lasting to 16Z. VFR transition could occur anytime between 1730Z and 19Z.
26/1208 AM.
Small Craft Advisory (SCA) level wind gusts expected to increase early today across the northern outer waters and will expand south through today and into the weekend. SCA winds will be strongest on Saturday, and will reach into the nearshore waters along the Central Coast and Santa Barbara Channel at times (more often than not). Local gusts may approach 35 kt near Pt. Conception Saturday evening into the overnight hours. Seas will near 10 ft Saturday evening through at least Monday morning. Beyond, conditions look to quiet down a bit through mid next week.
Ca, NONE. PZ, Small Craft Advisory in effect until 9 AM PDT Monday for zones 670-673-676. (See LAXMWWLOX).
