Santa Cruz Island to San Clemente Island to 60 NM offshore including San Nicolas and Santa Barbara Islands Marine Forecast
|Today...Se Portion, Ne Winds 20 To 30 Kt Becoming N 15 To 25 Kt In The Afternoon. Elsewhere, E Winds 10 To 15 Kt. Combined Seas 7 To 10 Ft Dominant Period 13 Seconds, Subsiding To 6 To 8 Ft Dominant Period 13 Seconds In The Afternoon.|
|Tonight...Nw Winds 10 To 15 Kt With Gusts To 20 Kt, Becoming N 5 To 10 Kt After Midnight. Wind Waves 1 To 3 Ft. Nw Swell 6 To 8 Ft At 13 Seconds, Subsiding To 4 To 6 Ft At 13 Seconds After Midnight.|
|Mon...E Winds 10 To 15 Kt, Becoming Se 10 Kt In The Afternoon. Wind Waves 2 Ft Or Less. Nw Swell 4 To 6 Ft At 12 Seconds.|
|Mon Night...Winds Variable 10 Kt Or Less, Becoming Nw 5 To 10 Kt After Midnight. Wind Waves 2 Ft Or Less. Nw Swell 4 To 6 Ft At 12 Seconds.|
|Tue...Winds Variable 10 Kt Or Less, Becoming Sw 10 Kt In The Afternoon. Wind Waves 2 Ft Or Less. Nw Swell 4 To 6 Ft At 13 Seconds.|
|Tue Night...Nw Winds 5 To 10 Kt. Wind Waves 2 Ft Or Less. Nw Swell 5 To 7 Ft At 13 Seconds. Slight Chance Of Showers After Midnight.|
|Wed...Nw Winds 15 To 20 Kt With Gusts To 25 Kt. Combined Seas 6 To 8 Ft. Chance Of Rain.|
|Thu...Nw Winds 10 To 15 Kt With Gusts To 20 Kt. Wind Waves 1 To 3 Ft. Nw Swell 4 To 6 Ft. Patchy Fog.|
| Area Forecast Discussion|
National Weather Service Los Angeles/Oxnard CA
828am PST Sunday Feb 28 2021
Gusty northeast winds will occur across most of Ventura and LA counties today. It will be dry with clear skies through Tuesday. Clouds will increase and a chance of rain will develop on Wednesday.
.SHORT TERM (TDY-TUE)...28/827 AM.
Another day, another round of Santa Ana winds (just the story of this Winter). Currently, northeasterly winds are gusting pretty strongly across Ventura/LA counties with gusts 60-75 MPH in the mountains and 35-55 MPH across the valleys and coasts. As usual in Santa Ana patterns, winds across San Luis Obispo and Santa Barbara counties are much weaker (gusts 15-30 MPH) and more localized. Looking at satellite and surface observations, skies are mostly clear this morning.
Forecast-wise for the immediate short term, main issue will continue to be the winds. Current (15Z) LAX-DAG gradient checks in at -6.0 MB which is providing good surface support while decent upper level wind/thermal support continues aloft. So with some morning atmospheric mixing, expect winds to increase a little bit before slowly diminishing in the afternoon. So, current slate of HIGH WIND WARNINGs and WIND ADVISORIES looks spot-on. As winds start to diminish this afternoon, will need to replace the warnings with advisories and likely extend some areas into the evening. Otherwise, sunny skies can be expected today with coastal/valley temperatures a few degrees above normal.
Overall, current forecast has great handle on the immediate short term. Will need to issue an update later this morning as a couple warnings will need to be adjusted to advisories. Otherwise, no significant updates are anticipated at this time.
***From Previous Discussion***
Last nigheights northerly winds have shifted to the northeast and have increased in speed. Warning level gusts are occuring right now in the LA mtns and will filter into the VTA mtns, San Fernando Vly and Santa Monica mtns later this morning. Advisory level winds will occur across the rest of VTA/LA counties save for the Antelope Vly. These warning and advisory level winds are the result of between 4 and 6 MB of offshore flow from both the E and W along with strong northerly upper level support and a dash of cold air advection. While the winds will subside in the afternoon areas currently under a warning will likely have advisory level gusts through early evening.Skies will be clear today. Most of the coasts will warm today due to the offshore compressional flow (The SBA south coast where the lack of northerly offshore flow will allow for an earlier seabreeze and max temps will cool about 8 degrees. The vlys will cool a few degree as there will not be enough adiabatic heating to offset the cool air advection from the interior. Most of the interior of LA and VTA counties will cool as cool air filters in, but the interior of SBA and SLO will warm as they had the best cool air advection ydy.
Monday will start off breezy but there will be 2 to 3 MB of onshore trends and there will not be much of any upper or thermal support. There may be a need for some low low end advisories in the LA mtns, Santa Clarita Vly and the vlys either side of the VTA/LA county line in the morning. It will be another sunny day and most areas will see a few degrees of warming save for the immediate coast where the lesser winds will reduce the compressional heating and allow for an earlier sea breeze.
A small ridge will Probability of Precipitation up over the state on Tuesday in response to an upper low moving southward over the east Pacific. This low will spin enough mid and upper level clouds over the area to make it a partly cloudy day. Further weakening of the morning offshore flow and actual onshore flow in the afternoon will bring several degrees of cooling to most areas. The ridge will allow the Antelope Vly to warm a few degrees.
.LONG TERM (WED-SAT)...28/327 AM.
The GFS and EC and most of the ensemble members have come into better agreement about the Wednesday forecast. It is now very likely the the upper low will up into the California Bite and into the VTA/LA area before moving through the state. Fairly confident that there will be some rain south of Pt Conception but less confident exactly when during the day or evening. Rainfall amounts will be under a third of an inch and likely much lower. Good confidence that this rain will not create any unusual weather hazards. Snow level will be near 5000 feet but not much actual snow fall is expected maybe a few inches in the higher elevations of the San Gabriels. The day may start out partly cloudy but will soon turn mostly cloudy. The clouds and lower hgts will bring cooling the entire area and max temps will end up a few degrees blo normal.
A little ridge will bring two days of warming and maybe some marine layer stratus across the coasts on Friday. Friday's max temps will be above normal save for the beaches.
The EC and enough of its ensemble members bring rain to the Central Coast on Saturday to warrant a slight chance of rain along with some clouds. This is in opposition to the deterministic GFS which had dry ridging with warmer conditions. So overall a fairly low confidence forecast.
Across the outer waters... Winds will continue to diminish today and will be below Small Craft Advisory (SCA) level by late morning in the northern and central outer waters and by late afternoon in the southern outer waters. There is a sixty five percent chance of SCA (Small Craft Advisory) level winds on Wednesday, otherwise conditions will remain below SCA (Small Craft Advisory) level through the remainder of the forecast period.
Across the nearshore waters of the Central Coast... Winds and seas will continue to diminish today and will be below SCA (Small Craft Advisory) level by late morning. There is a sixty five percent chance of SCA (Small Craft Advisory) level winds on Wednesday, otherwise conditions will remain below SCA (Small Craft Advisory) level through the remainder of the forecast period.
Across the inner waters south of Point Conception... Winds will be elevated and gusty near Point Conception today but will remain below SCA (Small Craft Advisory) level. Winds from Point Mugu to Santa Monica and out to the Channel Islands including Catalina Island will be offshore to gale force until midday and the winds will create rough and steep wind waves of 3 to 5 feet. The winds will diminish to SCA (Small Craft Advisory) level through late afternoon and then to below SCA (Small Craft Advisory) level. The winds and waves will likely affect the unprotected front side of Catalina Island and produce dangerous conditions on northeast facing harbor entrances including Avalon and Two Harbors. Otherwise and elsewhere, conditions will be below SCA (Small Craft Advisory) level.
The large northwest swell that has brought high surf across the Central Coast will continue to subside through today. There will be breaking waves of 6 to 10 feet with local sets to 12 feet across west to northwest facing beaches during early morning hours, then the surf will subside to below advisory level by midday. Dangerous rip currents will continue through the day.
.LOX WATCHES/WARNINGS/ADVISORIES... CA...High Surf Advisory in effect until 10am PST this morning for zones 34-35. (See LAXCFWLOX). Wind Advisory in effect until 3pm PST this afternoon for zones 40-41-44-45. (See LAXNPWLOX). High Wind Warning in effect until noon PST today for zones 46-547. (See LAXNPWLOX). High Wind Warning in effect until 3pm PST this afternoon for zones 53-54-88. (See LAXNPWLOX). Wind Advisory in effect until noon PST today for zone 87. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 9am PST this morning for zones 645-670-673. (See LAXMWWLOX). Small Craft Advisory in effect until noon PST today for zone 650. (See LAXMWWLOX). Gale Warning in effect until noon PST today for zone 655. (See LAXMWWLOX). Small Craft Advisory in effect until 3pm PST this afternoon for zone 676. (See LAXMWWLOX).
.HAZARD POTENTIAL OUTLOOK (TUE-SAT).
There is a possibility of widespread rain Tuesday night and Wednesday.