25/212 AM.
Marine layer clouds with patchy fog will reoccur each night from the coasts to the coastal valleys, expanding into the valleys into this weekend. Temperatures will trend cooler, with below normal temperatures through the weekend.
(tdy-Sun), 25/1120 AM.
Late morning satellite shows marine stratus layer beginning to recede primarily along the southern coast thus far. Onshore flow in quasi-zonal flow aloft will result in deepening of the marine layer over the next several days. Expect low stratus/fog along coastal areas and valleys.
High temperatures today are expected to warm to within a few degrees of yesterday's max temps. Mid- to high- level clouds will begin to descend through CA early tomorrow morning as pressure heights continue to fall due to the deepening PacNW low pressure system. Increasing cloud cover will further inhibit daytime warming throughout the week with today marking the beginning of a cooling trend through early next week. Expect daytime temperatures to cool by several degrees each day through Sunday before we begin to warm up again. Have decreased Max T from the NBM solution today and tomorrow by blending with yesterday's Obs and several other model solutions that are running cooler. Locations near the coast will warm into the upper-60s to low-70s while areas further inland will reach the upper-80s over the next few days.
Winds will remain light today but will gradually turn more northerly and increase beginning tomorrow evening as the pressure gradient tightens through Saturday, making this the breeziest day of the period. At this time there is a 45% to 80% probability of 35 mph wind gusts across portions of the Antelope Valley as early as Friday afternoon with more widespread chances on Saturday. Offshore winds will also increase to around 35 to 45 mph across the southern extent of Santa Barbara county Friday and Saturday evenings.
(Mon-Thu), 25/1133 AM.
PacNW low pressure system will continue rotating northward into Canada with another closed low forming over Washington early next week. Ensemble solutions begin to differ in the details heading into middle of next week but all feature general troughing for the upper-level pattern over CA through late next week. This will keep onshore flow in place with low stratus/fog along coastal areas and valleys each evening and morning. Winds will run lighter next work week. Temperatures will remain fairly consistent into mid- to late next week, with daytime highs right around climatological norms to slightly above.
25/2101z.
At 1715Z at KLAX, the marine layer was 2200 ft deep. The top of the inversion was at 3900 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. There is a 15% chance that CIGs do not clear, and a 30% chance of intermittent CIGs from 25/21Z through 26/01Z. Generally expecting MVFR CIGs 010-018, but likely CIGs fall to around IFR 008 from 26/05Z-10Z. No significant east wind component expected.
KBUR, Moderate confidence in TAF. Arrival of IFR CIGs should be accurate within +/- 2 hours of current forecast. No wind issues expected.
25/134 PM.
NW winds will increase to Small Craft Advisory (SCA) levels Thursday evening across the northern waters and will expand to the south Friday 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 from 6 PM this evening to 9 AM PDT Monday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect from 9 PM this evening to 9 AM PDT Monday for zone 673. (See LAXMWWLOX). Small Craft Advisory in effect from 3 AM Friday to 9 AM PDT Monday for zone 676. (See LAXMWWLOX).
