East Santa Barbara Channel from Pt. Conception to Pt. Mugu CA including Santa Cruz Island Marine Forecast
|Today...Nw Winds 10 To 15 Kt With Local Gusts To 20 Kt, Becoming W 15 To 25 Kt With Local Gusts To 30 Kt In The Afternoon. Strongest Western Portion. Combined Seas 5 To 7 Ft Dominant Period 14 Seconds. Patchy Drizzle In The Morning.|
|Tonight...Nw Winds 15 To 25 Kt With Gusts To 30 Kt. Combined Seas 6 To 8 Ft Dominant Period 15 Seconds.|
|Tue...Nw Winds 15 To 20 Kt, Becoming W 15 To 25 Kt In The Afternoon. Strongest Eastern Portion From Ventura To Point Mugu. Combined Seas 4 To 6 Ft Dominant Period 15 Seconds.|
|Tue Night...W Winds 15 To 20 Kt, Becoming 10 To 15 Kt After Midnight. Wind Waves 2 To 3 Ft. W Swell 4 To 6 Ft At 14 Seconds. Chance Of Rain In The Evening, Then Rain Likely.|
|Wed...W Winds 10 To 15 Kt, Becoming 15 To 20 Kt In The Afternoon. Wind Waves 2 To 3 Ft. W Swell 5 To 7 Ft At 14 Seconds. Rain In The Morning. Slight Chance Of Tstms. Rain Likely In The Afternoon.|
|Wed Night...W Winds 15 To 20 Kt, Becoming Nw 10 To 15 Kt After Midnight. Wind Waves 2 To 3 Ft. W Swell 5 To 7 Ft At 13 Seconds. Chance Of Showers In The Evening. Slight Chance Of Tstms.|
|Thu...Nw Winds 10 To 15 Kt. Wind Waves 1 To 3 Ft. W Swell 4 To 6 Ft. Slight Chance Of Showers.|
|Fri...Nw Winds 10 To 15 Kt. Wind Waves 1 To 3 Ft. W Swell 4 To 6 Ft.|
| Area Forecast Discussion|
...UPDATED National Weather Service Los Angeles/Oxnard CA
1042am PST Monday Mar 8 2021
Updated aviation section
Strong onshore flow will keep a cooler air mass in place with through Tuesday. Rain and low elevation snow along with gusty winds is expected for the region late Tuesday through Thursday night as a cold storm system moves over the region. A modest warming trend is expected for next weekend as high pressure builds in. High temperatures will remain below normal for this time of year.
.SHORT TERM (TDY-WED)...08/1041 AM.
The latest visible imagery shows low clouds are clearing away from the northern areas late this morning and scattering out across the Southland. Strong onshore flow in place across the area will keep a cooler air mass across the region today. KLAX AMDAR soundings show a deep moist layer in place up to around 6000 feet. The marine layer deepened enough to allow colder air aloft to weaken marine inversion. A deck of stratocumulus clouds will likely linger across the Los Angeles Basin into this afternoon. A reverse clearing (clearing from the coast before the valleys) day is shaping up for today. As the sun sets this evening, clouds should start to fill back into the Southland, albeit it will be less cloudy than last night and this morning due to the weaker marine inversion. The cloud forecast is a bit more uncertain in terms of areal coverage for the Southland. North of Point Conception, there is a better shot of more solid cloud coverage due to the marine inversion reforming late tonight and into Tuesday morning as an upper-level trough inches closer to the region.
A northerly surface pressure gradient developing today will bring marginally gusty northerly winds to southern Santa Barbara County tonight. A wind advisory will likely be added a bit later this morning for this evening and late tonight.
The main problem of the day is the cold storm system currently sitting near 47N and 136W, or about 1300 miles northwest of Los Angeles. This storm system will affect the region for extended period of time beginning Tuesday night. A rain band looks to move into the region late Tuesday afternoon through Wednesday morning, then a cold and unstable air mass will continue showers with low snow levels down to 2500-3500 feet. Accumulating snowfall will likely affect travel through the Interstate 5 Corridor and on Highway 14, and some accumulation cannot be ruled out on the Cuesta Pass in San Luis Obispo County. As 700 mb temperatures drop to -12 degrees Celsius, a rain-snow mix with small hail or graupel could fall down to around the 2000 foot elevation level. Gusty winds are also possible with this storm system as well. Wind advisories may be needed as soon as Tuesday afternoon for portions of the area. There is also a potential for thunderstorms across the area, possibly producing brief locally heavy rainfall. A winter storm watch will be left intact for now as there is still some differences in timing.
***From Previous Discussion***
An upper low will drop to a position about 400 miles west of Eureka by late Tuesday morning. Between stratus development and increasing mid/high clouds, expect skies to become mostly cloudy across the region tonight and remain so on Tue, though there could be a bit of sun Tuesday morning across southern and eastern sections. There is a slight chance of rain on the immediate Central Coast by late Tuesday morning, with the chance of rain possibly spreading as far south as the city of Santa Barbara by late afternoon. Max temps will drop another couple of degrees Tue, and will be 6-12 degrees below normal in most areas. Gusty west winds will likely reach advisory levels again in the Antelope Valley Tue.
The upper low will move eastward to a position just off the coast of northern California late Tuesday night, then move slowly southward to just west of San Francisco Wednesday afternoon. A trough will extend southward from this low with a decent west-southwest jet aimed at the forecast area Late Tuesday night, then shifting south during Wed. A deep layer of southwesterly flow through the atmosphere will transport plenty of moisture from the Pacific into the region Tuesday night and Wed. Rain will become likely across all but southern and eastern L.A. County by late Tuesday night, where there will be a chance of rain, then rain is expected across the region Wed. Though precipitable water values still do not look very high, there will decent dynamics due to good height falls and the placement of the jet. In addition, favorable southwesterly flow should provide some orographic enhancement of the precipitation on and below southwest facing mountain slopes. Expect periods of rain, possibly heavy at times late Tuesday night up north, and Wednesday across most of the region. With the very cold air aloft, there will also be the threat of some thunderstorms north of Pt. Conception late Tuesday night and Wed, and across L.A. and VTU Counties by Wednesday afternoon. Any thunderstorms could produce briefly higher rainfall rates and possibly small hail.
As the low tracks southward across the region Wednesday night, steady precipitation will turn to showers, but the slight chance of tstms should continue, especially across southern sections.
Snow levels will be rather low for much of this event, dropping to around or below 4000 feet by Wednesday morning, then possibly down to 3000 feet or even lower Wednesday night and early Thu. This could bring accumulating snow and dangerous driving conditions to higher elevations of Interstate 5 and possibly Highway 14. A WINTER STORM WATCH remains in effect for the mountains of SBA, VTU and L.A. Counties excluding the Santa Monicas. Some snow is possible in the foothills around the Antelope and Cuyama Valleys. Needless to say, it will be very cool across the region Wed, with temps 10 to 18 degrees below normal in most areas.
Rainfall totals are generally expected to average one half to one inch, except locally 1.5 inches or possibly higher in the foothills and mountains below the snow level. In the mountains above 4500 feet, snow accumulations of 6 to 12 inches are expected, with local totals over 15 inches possible.
It should be noted that the 00Z and the 06Z runs do not look as unstable or as wet for the region as did previous runs, so if that trend continues, precipitation totals may have to be scaled back. For now, have kept the forecast very similar to previous ones, since the basic pattern has changed little.
.LONG TERM (THU-SUN)...08/512 AM.
The upper low will track to the east of the region Thu, but the GFS shows a second weak center developing across near Catalina Island. There will certainly be enough moisture and instability across the region to keep a slight chance or chance of showers in the forecast. The big question is how plentiful will those showers be. At this point, it appears the best chance of showers will be across L.A. and eastern VTU Counties. In addition, lifted index values indicate increasing instability on Thu, so a slight chance of thunderstorms may actually have to be added to the forecast for at least L.A. County. Expect dry weather Fri through Sunday with some warming, more so if the EC if correct since it shows higher heigheights across the region. Overall though, expect temps to generally remain below normal through the weekend.
A moderately strong storm will move through the coastal waters Tuesday through Thursday bringing a chance of rain and slight chance for thunderstorms.
For the Outer Waters... Small Craft Advisory (SCA) thresholds will remain in effect through late tonight, but will likely continue through much of the week due to hazardous seas with swells persisting between 9 and 11 feet through at least Thursday evening. There will also be periods of gusty SCA (Small Craft Advisory) level winds as well. Strongest winds will occur for areas South and west of Point Conception through Tuesday night then becoming more widespread across the entire outer waters after that. There is a 60% chance for gusty NW winds to continue through Friday.
For the Inner Waters north of Point Sal... SCA (Small Craft Advisory) level winds and seas will continue through late tonight with a brief lull in winds in the morning hours. Seas will diminish early on Tuesday but then increase to SCA (Small Craft Advisory) level again by Tuesday night and continue through Wednesday. Winds will remain below SCA (Small Craft Advisory) level Tuesday and Wednesday and both winds and seas will be below SCA (Small Craft Advisory) level Thursday and Friday.
For the Inner Waters south of Point Conception... SCA (Small Craft Advisory) is in effect for gusty W to NW winds from noon today through 3am Tuesday morning. Winds will diminish late each night. Expect two more afternoon and evenings of SCA (Small Craft Advisory) level winds for the entire inner waters Tuesday and Wednesday as well. Otherwise, conditions will remain below SCA (Small Craft Advisory) levels.
A strong storm across the Gulf of Alaska will cause a NW swell 10 to 11 feet to develop across the coastal waters adjacent to the Central Coast late this afternoon. This swell will persist through much of the week. This will translate into surf across northwest and west facing beaches between 8 and 12 feet along with dangerous rip currents late this afternoon and continue through at least next Thursday afternoon. There will be peak periods where local sets to 14 feet will occur tonight and again on Wednesday and Thursday.
Some of the swell energy will filter into the SoCal Bight mainly into the inner Santa Barbara Channel towards the Ventura Coast where elevated surf 3 to 6 feet is expected tonight through Wednesday. There is a chance that higher surf 6 to 8 feet could affect the Ventura County Coast by Wednesday evening. If this is the case, a High Surf Advisory will likely need to be issued at that time through at least Thursday evening.
.LOX WATCHES/WARNINGS/ADVISORIES... CA...High Surf Advisory in effect from 3pm this afternoon to 9 PM PST Thursday for zones 34-35. (See LAXCFWLOX). Winter Storm Watch in effect from Tuesday evening through Thursday evening for zones 52>54. (See LAXWSWLOX). Wind Advisory in effect until 9pm PST this evening for zone 59. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 3am PST Tuesday for zones 645-650-655-670-673-676. (See LAXMWWLOX).
.HAZARD POTENTIAL OUTLOOK (WED-SUN).
High surf and dangerous rip currents are likely through the middle of the week. Gusty west to northwest winds will create driving and boating hazards at times through Wednesday. A winter storm will bring rain and snow to the area Wednesday and Thursday.