28/1214 AM.
The remnants of Tropical Storm Juliette will drift over the region through this evening. It will be cooler and cloudier today but with a jump in humidity. A few light showers are possible, across Los Angeles County through this evening. Benign weather with near normal temperatures is forecast for holiday weekend and into next week.
(tdy-Sat), 28/259 AM.
The remains of TS Juliette have been swept into a short wave trof which is moving from the SW to the NE. The deepest moisture is still to the south of San Diego and this is where the rain is falling. The high cloud shield associated with the trof/debris has moved as far north as SBA county and overcast skies have resulted. Most high rez mdls keep the rain to the south of LA county, however, historically the mdls have greatly struggled with forecasting rain from systems coming from this direction and think there is a 20 to 30 percent chc that rain will fall across southern or eastern LA county. Rainfall amounts, if any, will be on the light side. The moist air is in a fairly stable regime and with a big cloud shield to prevent sfc heating the odds of convection are pretty low. The best chc for precipitation will be later this afternoon. The huge cloud shield will bring 4 to 8 degrees of cooling to most of the area except for SLO county where the sunnier skies will allow for 3 to 5 degrees of warming.
The chance of rain and the clouds will end this evening leaving mostly clear skies in their wake. Its about a 50-50 proposition that low clouds will develop tonight across coastal sections south of Pt Conception. The Central Coast will likely see low clouds develop overnight.
Friday will be a mostly sunny day and the return of sunshine combined with rising hgts from an expanding upper high will drive up temperatures by 4 to 8 degrees. Look for 80s across the csts away from the nearshore area and 90s in the vlys.
Weak offshore flow from the north, only weak onshore flow to the east and no eddy should all combine to keep the low clouds away from areas south of Pt Conception. The Central Coast should have some low clouds. Hgts continue to rise as the upper high to the east bulges westward. Hgts will climb to 590 dam. Most areas will see 2 to 4 degrees of warming, but the Central Coast will warm by 3 to 6 locally 8 degrees as a little north flow develops. This warming will bring the max temps up to above normal. Vly highs will range from 90 to 102 degrees.
(Sun-Wed), 28/1214 AM.
Benign weather on tap for the xtnd fcst. An upper high will push in from the east On Sunday and Monday and then weaken Tue and Wed as it sits over the state. Hgts will rise from 589 dam Sun to 592 dam Mon and Tue only to fall to 590 dam on Wed. Onshore flow will not be that strong and will likely be slightly offshore from the north in the morning.
The marine layer stratus pattern has been tough to fcst this month. Right now the best chc for low clouds during this period will be the Central Coast and the Santa Ynez Vly. There will probably be some morning low cloudiness across the LA/VTA csts as well but this is less certain.
There will be little in the way of day to day temperature change. Look for 70s near the beaches with 80s a little further inland. The vly temps will mostly be in the 90s with some 100 degree readings possible in the western San Fernando Vly.
28/1243z.
At 1116Z at KLAX, the marine layer was 500 ft deep, with an inversion top of 2600 ft and a temperature of 25 C.
Good confidence in TAFs. There is 15 percent chc of light rain for sites KSBA and southward after 12Z (increasing to 20 percent after 18Z for KSMO, KLAX and KLGB). There is a 10-20% chance of IFR/MVFR cigs for coastal/valley sites until 16Z and again after 06Z Friday.
KLAX, High confidence in TAF. There is 15 percent chc of light rain aft 12Z increasing to 20 percent after 18Z. There is a 30 percent chc of BKN060 conds after 18Z. Good confidence that any east wind component will be under 5KT.
KBUR, High confidence in TAF. There is 15 percent chc of light rain after 12Z.
28/259 AM.
High confidence in relatively light winds and small seas through at least Friday morning, except for localized northwest wind gusts of 20 to 25 knots from Point Conception to San Nicolas Island this afternoon and evening. There is also some uncertainty in winds this afternoon over the waters south of the Channel Islands, and the area could see periods of south to easterly winds, especially on Friday across the San Pedro Channel (local gusts to 25 kt possible).
High confidence in increasing northwest winds and seas beyond 20 miles from shore Friday through Labor Day Weekend. Small Craft Advisory (SCA) will be likely at times across the outer waters, with a 30% chance of GALES for the outer waters north of Point Conception late Saturday.
Remnant moisture from Tropical Storm Juliette will bring a slight chance of showers and thunderstorms to the coastal waters between San Nicolas Island and the Santa Monica Bay and south this morning through early Friday morning. Additionally, a southerly swell from Juliette will arrive today and continue into Saturday. A longer period but lower height southerly swell from the Southern Hemisphere will follow and continue into early next week. Hazardous rip currents will be common across the beach of Ventura and Los Angeles Counties over Labor Weekend.
Ca, NONE. PZ, NONE.
