01/215 AM.
Mostly quiet weather is expected through the coming week, except for gusty north to northwest winds across the mountains and Antelope Valley Sunday night through Monday. During this time, there will also be a chance of light snow possible over the Tejon Pass.
(tdy-Mon), 01/302 AM.
Looks like a Chamber of Commerce day today. An upper lever low will slide to the south and have little or no effect on the fcst area. The low was originally forecast to be further north which would have increased the odds of some marine layer clouds but now it looks like mostly sunny skies. Hgts rise to about 568 dam and max temps should jump 4 to 8 degrees and end up a couple degrees either side of 70. Despite this warming max temps will still be a few degrees under their normals.
An eddy will likely spin up tonight as a result of the strong and persistent offshore winds. This will likely generate a good sized marine layer cloud deck that will cover most of the csts and the lower vlys. A weak northerly offshore push will likely keep the SBA south coast fairly clear. It will also bring gusty 30 to 40 mph wind gusts to the Santa Ynez range to the I-5 corridor.
A strong onshore push to the east will develop on Sunday as an upper low moves into the north of the state. This near 8 mb onshore push will delay clearing of the low clouds and will bring stronger than normal westerly winds to the coasts and through the Soledad Pass area and the Antelope Valley. The onshore flow and lowering hgts will combine to lower max temps 2 to 5 degrees.
A cold inside slider will move down the CA/NV border Sun night and Monday. Strong northerly flow will develop. The upslope flow along the north slopes of the Kern County line will generate clouds and and a chc of showers there. Snow levels will fall quickly to 3000 ft and the Grapevine/Tejon Pass will likely see some snow. ensemble spreads for the snow range from a trace to 2 inches and 1 inch is the most likely. Marine layer clouds will also persist at many coastal locations. Even though there is not much a N to S sfc gradient, the stage will be set for a significant wind event. A low level northerly jet coming down the back side of the low will combine with a cold air advection to produce very strong winds. There is a chc warning level winds in excess of 58 mph will develop across the mtns and Antelope Vly as early as 5am Monday although it is more likely they will arrive more towards afternoon. Max temps will plummet under the cold air advection and will end up in the mid 50s to lower 60s across the coasts and vlys.
The north winds will peak Monday evening and there is a chc warning level gusts will make it into some of the interior vlys. Wind advisories will be likely for many other areas as well.
(Tue-Fri), 01/309 AM.
Ensemble based forecasts are in decent (but not great) agreement as are the deterministic medium range mdls for the Tue to Fri xtnd period.
All agree there will be some sort of broad northwesterly cyclonic flow over the area Tue and Wed. The flow will shift to the west on Thu as a sharper trof digs down and on Friday the trof or weak cut of low will approach the southern half of the state. There will be weak offshore flow from the north and generally weak onshore flow to the east.
The weather will be pretty dull. Skies will be mostly clear or partly cloudy depending on how much mid or high level clouds drift overhead in the upper level flow. It does not look like there will be much in the way of marine layer clouds although that is not a guarantee with the onshore push to the east continuing. There will be 2 to 4 degrees of warming each day but even that will not bring max temps up to normals. By Friday max temps will be mid 60s to mid 70s which since it is April will still be a few degree under the seasonal norms.
01/1020z.
At 0716Z at KLAX, there was no marine layer nor an inversion
High confidence in most TAFs. There is a 25% chance of LIFR conditions at KSMX until 17Z and a 25% of IFR conditions at KSMO/KLAX/KLGB until 17Z.
KLAX, Moderate confidence in TAF. There is a 25% chance of 4SM BR BKN008 conditions until 17Z. No significant easterly wind component is expected.
KBUR, High confidence in TAF.
01/317 AM.
For the Outer Waters, moderate to high confidence in current forecast. High confidence in Small Craft Advisory (SCA) level persisting through Sunday. For Sunday night through Wednesday, high confidence in SCA level winds and seas. Additionally, there is a 60-80% chance of widespread Gale force winds Sunday night through Tuesday.
For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. Moderate confidence in winds and seas remaining below SCA levels until this evening. On Sunday, high confidence in winds staying SCA level and remaining at SCA levels through Tuesday with SCA level seas developing Monday/Tuesday. Additionally, there is a 60-70% chance of widespread Gale force winds Sunday night through Monday night. On Wednesday, there is a 50% chance of SCA level winds.
For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. High confidence in winds and seas remaining below SCA levels through this afternoon, then winds are expected to increase to SCA level for the western portion of the SBA Channel. For Sunday and Sunday night, high confidence in winds increasing to SCA levels and remaining at SCA levels through Tuesday. Additionally, there is a 60-70% chance of widespread Gale force winds Sunday night through Tuesday. On Wednesday, there is a 40-50% chance of SCA level winds continuing across western sections.
Ca, High Wind Watch in effect from late Sunday night through late Monday night for zones 345-353-376>383. (See LAXNPWLOX). PZ, Small Craft Advisory in effect from 9 PM this evening to 9 PM PDT Sunday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 9 PM PDT Sunday for zones 650-670. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM Sunday to 9 AM PDT Monday for zone 655. (See LAXMWWLOX). Small Craft Advisory in effect until 9 PM PDT Sunday for zones 673-676. (See LAXMWWLOX).
