21/829 PM.
Warmer than normal conditions will persist through the week, likely warmest Tuesday through Thursday. Dense fog will affect some coastal areas for at least the next few days. Breezy north winds will affect some areas by Monday.
(Sat-Tue), 21/831 PM.
***UPDATE***
Low clouds and dense fog have pushed into the coastal areas this evening south of Point Conception. A Dense Fog Advisory might be needed, but confidence is low as the current visibilities are just above what is needed and the scattered high clouds makes it really hard to track on satellite. Lowered temperatures a little at the coast because this fog will likely hug the coast through the morning if not the afternoon hours. Otherwise, the forecast remains on track.
***From Previous Discussion***
Temperatures dropped 5-10 degrees in most areas today as high pressure aloft weakened which allowed onshore flow to push in earlier and stronger than previous days. The onshore push also brought with it very dense coastal fog with visibilities a quarter mile or less right at the beaches.
The forecast remains largely unchanged from the last few days. Similar conditions expected Sunday with fog at the beaches and temps in the 80s inland with an isolated 90 in the warmest areas.
Another warming trend will begin Monday and peak Tue/Wed. Deterministic models have backed off the strength of the north/south gradients next week by around 50% which in theory should result in lighter winds and less downslope warming effects. However, ensemble forecast gradients were not available and it's possible the majority of those are still favoring a stronger northerly flow off the mountains. So there remains some uncertainty there. Also, NBM appears to be on board with northeast flow off the Santa Lucias early next week which would at least push highs there into the 80s to lower 90s along the Central Coast starting on Monday. Will have to give strong consideration to heat advisories there and can't yet rule that out for areas south of Pt Conception as well.
(Wed-Sat), 21/144 PM.
Tuesday through Thursday will be very warm days, but will not be record breaking like last week's. The upper high will not be overhead and hgts will be a few dam lower. Additionally while there will be offshore flow from the north there will be onshore flow to the east. Highs will continue in the 80s and 90s or 15 to 20 degrees above normal. There may be a need for heat advisories in the vlys but no warnings are anticipated.
The ridge weakens some on Friday and the onshore push to the east increases. This will likely bring 3 to 5 degrees of cooling to the csts and 1 to 3 degrees in the vlys.
There is growing confidence that the rest of the month will be dry. The AI-mdls still show some chc of light rain at the beginningof April.
22/0000z.
At 2248Z at KLAX, the marine layer was 400 feet deep. The top of the inversion was at 1800 feet with a temperature of 26 C.
Overall, moderate confidence in 00Z TAF Package. Have moved arrival times of marine layer stratus up by few to several hours. Expect VLIFR to IFR conditions for coastal sites south of Point Conception. Timing of flight changes could be off +/- 3 hours from current forecast.
KLAX, Moderate confidence in TAF. Generally expecting LIFR to IFR conds through mid-morning Sunday (002-006 with 1/2SM-2SM vsbys). No significant easterly wind component is expected.
KBUR, High confidence in VFR TAF.
21/833 PM.
For the Outer Waters, moderate to high confidence in current forecast. Today through Thursday, high confidence in a combination of Small Craft Advisory (SCA) level winds and seas. For tonight, there is a 60% chance of Gale Force wind gusts across PZZ670. Gusts to 35 kts will likely remain confined to northern portions. For Wednesday, there is a moderate chance of GALES. Likely to be focused during the afternoon thru overnight timeframe, and across western portions.
For the Inner Waters north of Point Sal, moderate to high confidence in current forecast. Conditions will remain below SCA levels through Sunday morning. For Sunday through Thursday, there is a 50-70% chance of SCA level winds during the afternoon and evening hours.
For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. For most of the southern Inner Waters, high confidence in winds and seas remaining below SCA levels through Thursday. The only exception will be the western half of the Santa Barbara Channel where there is a 20-30% chance of SCA level winds today through Thursday, focused during the afternoon and evening hours.
Areas of dense fog will impact the coastal waters through Sunday, focused across the waters inside the southern California bight. Visibilities of one nautical mile or less can be expected.
Ca, NONE. PZ, Small Craft Advisory in effect from noon to 9 PM PDT Sunday for zone 645. (See LAXMWWLOX). Gale Warning in effect until 3 AM PDT Sunday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect from 3 AM Sunday to 3 AM PDT Monday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Monday for zones 673-676. (See LAXMWWLOX).
