Point Piedras Blancas to Point Sal out 10 NM Marine Forecast
|Tonight...Nw Winds 15 To 25 Kt. Wind Waves 2 To 4 Ft. Nw Swell 8 To 9 Ft At 12 Seconds.|
|Thu...N Winds 10 To 15 Kt. Wind Waves 2 Ft Or Less. Nw Swell 8 To 9 Ft At 14 Seconds.|
|Thu Night...Nw Winds 10 To 15 Kt In The Evening, Becoming N 5 To 10 Kt. Wind Waves 2 Ft Or Less. Nw Swell 8 To 10 Ft At 15 Seconds.|
|Fri...N Winds 5 To 10 Kt, Becoming Nw 10 To 15 Kt With Gusts To 20 Kt In The Afternoon. Wind Waves 1 To 3 Ft. Nw Swell 7 To 9 Ft At 13 Seconds.|
|Fri Night...Nw Winds 10 To 20 Kt. Wind Waves 2 To 3 Ft. Nw Swell 7 To 9 Ft At 11 Seconds. Patchy Fog.|
|Sat...Nw Winds 10 To 15 Kt. Wind Waves 1 To 3 Ft. Nw Swell 5 To 7 Ft At 10 Seconds. Patchy Fog In The Morning.|
|Sat Night...Nw Winds 10 To 15 Kt. Wind Waves 1 To 3 Ft. Nw Swell 5 To 6 Ft At 12 Seconds. Patchy Fog.|
|Sun...Nw Winds 5 To 10 Kt. Wind Waves 2 Ft Or Less. Nw Swell 4 To 5 Ft. Patchy Fog.|
|Mon...Nw Winds 5 To 10 Kt. Wind Waves 2 Ft Or Less. Nw Swell 6 To 8 Ft. Patchy Fog.|
| 206 PM PDT Wed Oct 27 2021 |
Synopsis for the southern California coast and Santa Barbara Channel including the Channel Islands National Marine Sanctuary and National Park - PZZ600
at 21Z, or 2 PM PDT, a 1027 MB was 500 NM west of Point Conception extending toward Nevada. The large west to northwest swell will continue to subside through Thursday.
| Area Forecast Discussion|
...UPDATED National Weather Service Los Angeles/Oxnard CA
448pm PDT Wednesday Oct 27 2021
update for new aviation discussion
High pressure will continue.nue to build over the region and there will be weak to moderate offshore flow bringing a warming trend through Thursday. Cooler temperatures and a return of coastal overnight and early morning clouds are expected by the weekend.
Short Term - Today through Saturday
Overall, 12Z models in good synoptic agreement through the short term period. At upper levels, gradually weakening upper level ridge will remain over the area through Thursday then a trough will develop on Friday/Saturday as a low moves into Northern California. At lower levels, offshore flow will prevail through Friday morning with onshore flow returning Friday afternoon through Saturday.
Forecast-wise, main issue will be offshore winds. Based on 12Z guidance, offshore LAX-DAG gradients peak Thurday morning (NAM -5.0 MB and GFS -2.6 MB). As is usually the case, the NAM indicates better upper level support Thursday morning then the GFS or ECMWF. So, will generally split the difference, going with a low end advisory level event for Ventura and LA counties. So, will issue a WIND ADVISORY for the LA/Ventura mountains and the valleys (except for the San Gabriel Valley) mentioning gusts 35-45 MPH. Will leave the coastal zones out of the advisory for now, only anticipating localized gusts around 35 MPH. For Thursday night and Friday, the offshore gradients weaken and upper level support wanes. So any northeast winds through Friday will be weaker and more localized, not requiring any type of advisory. By Friday afternoon, the flow turns weakly onshore and continues through Saturday. So, no wind issues through this time period.
Otherwise, the combo of the upper level ridge and offshore flow will make Thursday the warmest day of the forecast period with most coastal/valley areas in the 80s to lower 90s. A cooling trend will begin on Friday and will continue.nue through Saturday as the flow switches to onshore and the upper level trough develops over the area.
As for clouds, skies will remain clear through Friday. For Friday night and Saturday, some marine layer stratus/fog will redevelop over the coastal plain. Otherwise, the clear skies will continue.nue through Saturday
Long Term - Sunday through Wednesday
For the extended, models continue to exhibit decent synoptic agreement. At upper levels, weak and transient, ridge moves over the area then a front moves across the state on Monday, followed by ridge building on Tuesday and Wednesday. Near the surface, onshore flow will continue.nue through Monday with some weak offshore possible on Tuesday/Wednesday.
Forecast-wise, Sunday looks to be a rather unremarkable day with cooler temperatures, some coastal stratus/fog and onshore winds. On Monday, the tail end of the previously mentioned front will graze areas north of Point Conception. Deterministic ECMWF (European Centre for Medium-Range Weather Forecasts) brings some light rain to the Central Coast while the Deterministic GFS is dry. Looking at the respective ensembles, ECMWF indicates decent chances (40-60%) of light, measurable rainfall while the GFS members indicate lesser chances (10-20%) of light, measurable, rainfall. The NBM brings some slight chance POPs for northwest San Luis Obispo county which looks like a decent compromise at this time between the GFS and ECMWF ideas.
For Tuesday/Wednesday, will expect warmer conditions at the upper level ridge builds overhead and weak offshore flow develops. At this time, do not anticipate any significant offshore winds, just enough offshore push to limit coastal stratus and bring the warmer temperatures.
High confidence that Small Craft Advisories (SCA) will remain in effect from the Central Coast to San Nicolas Island through tonight for a combination of winds and large seas. The seas continue to slowly subside from their Monday peak, but they remain very large. Dangerous breaking waves will continue.nue to pose dangers to boats and divers, especially near the rocks.
Northeast winds will form nearshore to the Central Coast Thursday morning, with a 30 percent chance of reaching SCA. Santa Ana winds will also lead to a 20 percent chance of SCA (Small Craft Advisory) winds from Ventura to Santa Monica Thursday, with little to no chance of significant impacts to Avalon.
A High Surf Advisory remains in effect for the central coast and the west facing beaches of Ventura County. The central coast will have breaking waves of 9 to 12 feet, mainly on west and northwest facing beaches, through 2 pm this afternoon.
For the west facing beaches of Ventura County, breakers will range from 6 to 8 feet through 2 pm. After 2 pm, all High Surf Advisories will be allowed to expire for this swell event.
NOAA Los Angeles/Oxnard CA Office: Watches - Warnings - Advisories
CA...Wind Advisory in effect from 3am to 3pm PDT Thursday for zones 44>46-53-54-88-547.
PZ...Small Craft Advisory in effect until 3am PDT Thursday for zones 645-670-673-676.
Hazard Potential Outlook (Saturday - Wednesday)
No significant hazards expected.