Santa Cruz Island to San Clemente Island to 60 NM offshore including San Nicolas and Santa Barbara Islands Marine Forecast
| Today...N Winds 15 To 25 Kt, Becoming Nw 20 To 30 Kt In The Afternoon. Gusts To 35 Kt. Strongest Nw Of San Nicolas Island. Combined Seas 8 To 11 Ft Dominant Period 13 Seconds. Patchy Fog In The Morning. |
| Tonight...Nw Winds 15 To 25 Kt With Gusts To 35 Kt. Strongest Nw Of San Nicolas Island. Combined Seas 8 To 11 Ft Dominant Period 13 Seconds. Patchy Dense Fog With Vsby 1 Nm Or Less In The Evening, Then Patchy Fog. |
| Sat...Nw Of San Nicolas Island, Nw Winds 20 To 25 Kt. Elsewhere, Winds Variable 10 Kt Or Less Becoming W 10 To 15 Kt In The Afternoon. Combined Seas 7 To 9 Ft Dominant Period 13 Seconds. Patchy Fog In The Morning. |
| Sat Night...Nw Winds 10 To 20 Kt With Gusts To 25 Kt, Becoming Ne 15 To 25 Kt After Midnight. Strongest Nw Of San Nicolas Island. Combined Seas 6 To 8 Ft Dominant Period 11 Seconds. |
| Sun...E Winds 15 To 20 Kt With Gusts To 25 Kt, Becoming W 10 Kt In The Afternoon. Wind Waves 1 To 3 Ft. W Swell 4 To 6 Ft At 11 Seconds. |
| Sun Night...W Winds 10 Kt In The Evening, Becoming Variable 10 Kt Or Less. Wind Waves 2 Ft Or Less. W Swell 3 To 5 Ft At 11 Seconds. |
| Mon...Sw Winds 5 To 10 Kt. Wind Waves 2 Ft Or Less. W Swell 3 To 5 Ft. |
| Tue...Nw Winds 10 To 15 Kt With Gusts To 20 Kt. Wind Waves 1 To 3 Ft. W Swell 3 To 5 Ft. |
| Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 1238pm PDT Fri September 25 2020 Synopsis 25/317 AM. Slight cooling trend for today across the region, then high pressure starts to build in allowing for a moderate warming trend this weekend. More significant warming expected early next week as offshore winds are expected to strengthen early next week with triple digit heat possible for valleys and highs reaching the 90s for some coastal areas, especially across Los Angeles and Ventura Counties through mid week. .SHORT TERM (TDY-SUN)...25/913 AM. The marine inversion was surface-based at VBG and around 1500 ft deep at LAX early this morning. There were no low clouds along or off the Central Coast, while S of Point Conception low clouds were fairly extensive along the coast up to Santa Barbara airport and extended inland to portions of the the L.A. County vlys. The low clouds are forecast to clear off the coast by midday, with sunny skies in all areas through the afternoon. There should be decent onshore gradients this afternoon (NAM forecast +6.5 mb LAX-DAG at 00Z) which will help to bring gusty SW to NW winds to the region, especially for the Central Coast, foothills, mtns and deserts. Hi temps today are expected to be several degrees above normal for the vlys, mtns and deserts, and a few degrees below normal for many coastal areas. The warmest vlys and lower mtns should reach the the upper 80s to low 90s this afternoon. A flat 590 dm upper level ridge will prevail over over the forecast area today. Over the weekend, an upper level hi will build just off the CA and OR coast. Upper level ridging will extend into southern CA, with H5 heigheights increasing to 590-591 dm by Sunday afternoon. The inversion will remain less than 500 ft deep on the central Coast thru the weekend, and around 1200 to 1400 ft deep for areas S of Point Conception. Marine layer stratus is forecast to move back into coastal areas of VTU/L.A. Counties tonight into Sat morning, with some minor extent into the San Gabriel Vly. Patchy low clouds should affect the Central Coast this evening then offshore flow should push any low clouds off the coast. For Sat night into Sunday morning, it looks only the VTU/L.A. County coast should have some low clouds. Otherwise, mostly clear skies will prevail across the region thru Sun. Pressure gradients will trend offshore to the E thru Sun. Offshore flow should prevail over SLO/SBA Counties during the night and morning hours, with light offshore flow further S. Some onshore flow will continue afternoons and evenings, except will remain offshore for interior areas thru the day on Sun. There should also be some gusty n canyon winds along over southern SBA County this evening, mainly W of Goleta, but winds should remain below Advisory levels. A warming trend is forecast over the weekend, with highs by Sunday 8-14 deg above normal away from the coast. Highs in the warmest vlys and lower mtns should reach the upper 80s to lower 90s Sat, and well into the 90s on Sun. .LONG TERM (MON-THU)...25/559 AM. The high res NAM-WRF model is now indicating a weak to locally moderate Santa Ana Wind event developing Monday morning. Strongest gusts look to be 35 to 45 mph across the usual wind prone passes and canyons of L.A. and Ventura Counties. With strong high pressure aloft locked in over much of the western states from Washington to Arizona and a storm system diving south out of Canada over the Rockies, cold air behind the system will build in over Utah/Col causing a tightening offshore gradient to develop Monday morning. The NAM- WRF is advertising LAX-DAG -5.5MB as this is the first run of the NAM to go out that far. The European model is showing a stronger offshore gradient on Tuesday, but the offshore trends look good for both Monday/Tue, with weaker offshore gradients continuing Wed/Thu. The bottom line is there will be hot and dry conditions across the forecast area with gusty Santa Anas a good possibilty both Monday and Tuesday mornings into the early afternoon hours. Tue/Wednesday are likely to be the hottest days with warmest valleys reaching 103-105 degrees while coastal areas across LA/Ventura Counties will reach the upper 80s to mid 90s. With the weak offshore lingering into Thursday, expect only a few degrees of cooling with best cooling likely across coastal areas as the seabreeze should kick in but still remain well above normal for coast and valleys. The Antelope Valley will remain in the mid 90s early in the week, then warm a few degrees as the offshore winds let up. Low clouds should remain off the coast, but there could be a few coastal areas that could see some patchy dense fog if fog makes it to the immediate coast possibly Wed/Thu mornings. There will be a few record-breaking temperatures possible during this event, even though it's not expected to be as hot as the early Sept heat wave. No heat watches are needed at this time, however, it's very likely that heat advisory levels will be reached in the valleys and possibly the mountains on the hotter days. The other weather factor next week will be the potential for large plume growth and rapid fire spread with any new or existing fires due to the weak instability and mixing heigheights above 10,000 ft each day. Marine 25/816 AM. Across the outer waters... Winds will be Gale force through late tonight then diminish to Small Craft Advisory (SCA) level into Sunday. The strongest winds will be in the afternoon and evening hours. Seas will remain large through Saturday morning then will slowly subside. Otherwise conditions will remain below SCA (Small Craft Advisory) level through the forecast period. Across the nearshore waters of the Central Coast... SCA (Small Craft Advisory) winds will continue through Saturday night and will be strongest in the afternoon and evening hours. Seas will remain large through Saturday morning then will slowly subside. Otherwise conditions will remain below SCA (Small Craft Advisory) level through the forecast period. Across the inner waters south of Point Conception... Winds will be elevated and gusty near Point Conception through Saturday night but conditions will remain below SCA (Small Craft Advisory) level through the forecast period. Patchy fog, locally dense with visibility under one mile, will continue through the weekend. The lowest visibility and most widely spread conditions will occur in the overnight and morning hours. .LOX WATCHES/WARNINGS/ADVISORIES... CA...High Surf Advisory in effect until 9am PDT Saturday for zones 34-35. (See LAXCFWLOX). PZ...Small Craft Advisory in effect until 9pm PDT Saturday for zone 645. (See LAXMWWLOX). Gale Warning in effect until 3am PDT Saturday for zones 670-673-676. (See LAXMWWLOX). .HAZARD POTENTIAL OUTLOOK (SUN-THU). Dangerously hot weather and near critical fire weather conditions are possible all of next week as strong high pressure builds across southwest California. |
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