Marine Weather and Tide Forecast for South Monrovia Island, CA

Page Links:   Change Location   One Page   HELP   Default setup   Tides Week   Tides   SF Current Maps   Save   Recall

---

NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION. Privacy and Cookie policy

---

---

7 Day Forecast for Marine Location Near South Monrovia Island, CA

   Hourly   EDIT   Help

---

Area Discussion for - Los Angeles/Oxnard, CA

      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
FXUS66 KLOX 081622 AFDLOX

Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 922 AM PDT Thu Jun 8 2023

SYNOPSIS
08/846 AM.

Some warming with a mix of clouds, sun, and mountain thunderstorm threat through Friday. Another low pressure system will bring cooler conditions and another increased threat of widespread showers and thunderstorms over the weekend, potentially similar to earlier this week. Warming to follow Monday through the middle of next week.

.SHORT TERM (TDY-SAT)...08/832 AM.

***UPDATE***

The sun woke up this morning to a very chaotic cloud pattern, with random splotches of low clouds around the area. This is in large part due to a very weak marine inversion left over from the low pressure system that moved through Tuesday and Wednesday. The inversion over Vandenberg was only 4 degrees Celsius while it was only 2 degrees over LAX airport. That inversion is usually 10+ degrees in June which usually leads to a blanket of June Gloom low clouds, but that blanket has a lot of holes today. As such, the afternoon cloud pattern is highly uncertain, but plenty of sunshine is the most likely outcome. This, along with a weak ridge aloft strengthening through the day, should add up to a healthy 5-10 degree jump over yesterday's temperatures, which is closer to normal but still 5-10 degrees below the mark. No significant winds worth mentioning. Convective parameters are still high enough to produce mountain showers and thunderstorms (-3 lifted index, 38 K-index, 2000 MUCAPE, and 850 millibar dewpoints of 10 degrees C). While these parameters are similar to the thunderstorm-free day yesterday, the added warming today in the mountains is enough to keep the slight chances going for the Ventura County Mountains and San Gabriel Mountains (our usual convective hot spots).

***From Previous Discussion***

Onshore flow will strengthen through the day as southwest flow aloft redevelops. Onshore pressure gradients are expected to become strongly onshore by late this afternoon. With the ridge departing and tightening the marine inversion through the day today, low clouds and fog should become more entrenched between tonight and Friday morning. NAM BUFR time height sections show a significant surge of marine air intruding into the marine layer depth as it deepens overnight tonight and into Friday morning.
with the amount of strong onshore flow developing, this makes some sense. For now, the forecast does not all in with the NAM solutions as HRRR and local 3-km WRF solutions are a little less aggressive in returning a more pronounced low cloud deck into the valleys. If NAM BUFR time heights section develop as progged, night through morning drizzle could develop late tonight and Friday morning.

With the marine layer depth deepening further into Saturday and Sunday, these days appears to be the better days for night through morning drizzle. The forecast adds a slight chance of rain to account for the drizzle possibility, but as details become clearer, the forecast will need to be refined to add this. A cooling trend should be expected between Friday and Sunday with some of the coastal and valley being shrouded in cloud coverage, keeping temperatures down.

Mentions of a slight chance of showers and thunderstorms linger for today and again on Friday over the mountains. A trailing vort max moving through the ridge could provide some lift today, then a difluent flow pattern has been progged consistently for last several days to develop on Friday. About a fifth of the EPS ensemble solutions and half of the CMC ensemble solution develop precipitation at KSDB during the afternoon and evening either today or Friday. With high-resolution multi-model solutions leaning toward a wetter solution over the mountains, the forecast keeps PoPs and mentions of showers and thunderstorms each day.

As the trough moves into the region over the weekend, the air mass will destabilize. A vast majority of the EPS, GEFS, and CMC ensemble members have rain at most airports across Southwest California between Saturday and Sunday, but the timing and exact amounts are the most uncertain aspects of the forecast. With the instability with the trough and it being June with a higher sun angle, a slight chance of thunderstorms was kept for now. Amounts will vary widely due to convective nature of storms. Forecast ensemble precipitable water mean values range between 0.60-0.80 inch, or close to 150 to 200 percent of normal, while some ensemble members throw decent CAPE values over portions of the region. CMC members kick out decent CAPE values between 600-1200 J/kg over KSDB, KWJF, and KPMD.

.LONG TERM (SUN-WED)...08/417 AM.

Strong onshore flow looks to remain in place through at least early next week as forecast ensembles keep a cooler air mass over the coast and valleys into Tuesday. EPS ensemble cloud cover means keep cloud cover close to 100 percent into Tuesday at KLAX, and into Wednesday for KSMX and KSBP. All this points to an continued cooler than normal weather pattern with night through morning low clouds and fog. Better clearing is possible for the valleys and inland coast after Tuesday.

AVIATION
08/1259Z.

At 1230Z, the marine layer at KLAX was 3600 feet deep. The top of the inversion was around 5500 feet with a temperature of 11 degrees Celsius.

Very disorganized cloud pattern across the region this morning.
Conditions were mostly low MVFR to MVFR, except IFR to VLIFR in the foothills and mountains. Expect cigs to scatter out in most areas by afternoon or rise to VFR levels, except may remain IFR in the foothills and mountains. Expect widespread MVFR cigs tonight, except IFR to VLIFR in the foothills and mtns.

KLAX...Low to moderate confidence in the 12Z TAF. There is a 20-30% chance of MVFR to low VFR cigs between 15Z and 21Z. There is a 20% chance that skies will remain clear tonight. No significant easterly wind component is expected.

KBUR...Low to moderate confidence in the 12Z TAF. There is a 20-30% chance of MVFR to low VFR cigs between 15Z and 21Z. There is a 20 to 30% chance that skies will remain clear tonight.

MARINE
08/916 AM.

Fairly high confidence in current forecast with winds and seas expected to remain below Small Craft Advisory (SCA) levels for all the coastal waters through much of the five day period.
There is a 30 percent chance of SCA level winds Saturday afternoon into Sat night across the outer waters.

BEACHES
08/921 AM.

Surf of 3 to 5 feet is expected on south facing beaches of L.A.
and Ventura Counties, with locally higher sets to 6 feet on some beaches. There will be a high risk of rip currents.

LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.

---

Weather Reporting Stations

   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map

toggle option: (graph/table)

Wind History for Los Angeles Pier S, CA

(wind in knots)    EDIT      (on/off)   Help

No data

---

Airport Reports

    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.

Link to 5 minute data for KEMT

toggle option: (graph/table)
Wind History from EMT (wind in knots)

---

Tide / Current Tables for El Segundo, Santa Monica Bay, California

   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data