21/950 AM.
Significantly cooler temperatures are expected through the end of the week. The weather will be unsettled and scattered showers are possible tonight through Friday. Warmer and drier conditions will resume early next week.
(tdy-Sat), 21/257 PM.
A weak low pressure system is currently spinning off over the coastal waters along the Central Coast, and is shuttling cooler temperatures and clouds into the SoCal region. Unsettled weather with scatted showers and highs in the 60s are expected through Friday. Winds have returned to onshore for the majority of the area, marking a significant change in the overall weather pattern compared to the previous many days of dry sunny days driven by offshore flow.
There is a 30-50 percent chance of rain at some point between tonight (Wednesday night) and Friday. This evening, scattered showers will be focused over the Central Coast and Santa Barbara County, followed by Ventura and LA Counties on Thursday and Friday. Rainfall intensity will be light to moderate, although there is a less than 10 percent chance of a heavier shower or thunderstorm with brief peak rainfall rates of 0.25 to 0.5 inches per hour. Heavier showers or thunderstorms will be most likely on Thursday across eastern Santa Barbara County, Ventura and Los Angeles Counties. Rainfall totals will be highly variable, but mostly under 0.25 inches, with the highest totals likely occur across south- facing slopes of Santa Barbara, Ventura, and Los Angeles Counties. Even so, high end rain fall totals top out at around 0.5 inch for favored areas such as the San Gabriel Mountains. Snow levels will generally be above 6500 feet with light snow accumulations possible at ski resort levels.
By Saturday, the center of the Storm system will be far to the south of SoCal, making way for more sunshine and warmer temperatures. However, strong winds aloft and surface pressure gradients will yield gusty northerly winds Saturday into Sunday, particularly across the mountains and the Interstate-5 Corridor.
(Sun-Wed), 21/237 PM.
The low pressure system will clear out of the region over the weekend, and a weak ridge of high pressure will set up early next week. This will allow for a gradual warming and drying trend, with chances for weak to moderate Santa Ana Winds at times. Highs early next week will rise to a couple degrees above normal, with high 60s to low 70s common. This warmer spell however will be much cooler than last week, when highs in the 80s were widespread.
A dry weather pattern is favored through the end of the month. The next signal for rain chances starts in early February.
21/1743z.
At 1638Z at KLAX, the marine layer was 800 fT deep. The top of the inversion was at 1900 ft with a temperature of 18 C.
High confidence in TAFs for desert airfields (KPMD & KWJF).
Low to moderate confidence for remaining TAFs. Timing of CIG/VSBY restrictions may be off by +/- 3 hours and categories by 1 or 2. Expecting -SHRA chances for coastal and valley sites, thus have included PROB30 groups from previous package.
KLAX, Low to moderate confidence in TAF. Generally expecting BKN/OVC 010-025 through the period, although could fall to 008 through 22/12Z. 20-40% chc of -SHRA 14-23Z. Moderate confidence that any east wind component remains under 8 kts thru the period.
KBUR, Low to moderate confidence in TAF. IFR-MVFR cigs likely to return after 06Z Thu. Forecast sounding and MOS guidance suggest that there exist a slight chance for LIFR CIGs to develop 06Z-12Z.
21/208 PM.
Winds and seas are expected to remain relatively calm through Thursday, then there is a 30 percent chance for Small Craft Advisory (SCA) winds across the Outer Waters and into the western Santa Barbara Channel Friday into Saturday morning. Another round of light Santa Ana winds is forecast to return Saturday night into Sunday, but chances are low for any impactful nearshore winds at this time.
Rain showers are possible from this afternoon through Thursday night, starting west and moving east through the timeframe. This activity could linger into early Friday morning across the waters adjacent to Los Angeles and Orange Counties.
There is a very low chance (5% chance) for a thunderstorm or two to develop on Thursday focused south of Point Conception.
Ca, NONE. PZ, NONE.
