Point Piedras Blancas to Santa Cruz Island CA between 150 and 250 NM Offshore Forecast
|Tonight...Sw Winds 10 To 20 Kt, Becoming W To Sw 5 To 15 Kt. Seas 7 To 12 Ft.|
|Tue...N To Nw Winds 5 To 15 Kt. Seas 9 To 13 Ft.|
|Tue Night...N To Nw Winds 10 To 20 Kt. Seas 11 To 13 Ft.|
|Wed...N To Nw Winds 15 To 25 Kt. Seas 10 To 12 Ft.|
|Wed Night...N To Nw Winds 15 To 25 Kt. Seas 9 To 11 Ft.|
|Thu...N Winds 20 To 25 Kt. Seas 10 To 13 Ft.|
|Thu Night...N To Nw Winds 20 To 25 Kt. Seas 9 To 14 Ft.|
|Fri...Nw Winds 15 To 25 Kt. Seas 7 To 13 Ft.|
|Fri Night...N To Nw Winds 15 To 25 Kt. Seas 7 To 10 Ft.|
|Sat...N To Nw Winds 20 To 25 Kt. Seas 9 To 13 Ft.|
|Sat Night...N To Nw Winds 20 To 25 Kt. Seas 10 To 13 Ft.|
| Area Forecast Discussion|
National Weather Service Los Angeles/Oxnard CA
229pm PDT Monday September 25 2023
Other than patchy low clouds and fog in coastal areas tonight and Tuesday morning, skies will be mostly clear through mid-week. Temperatures are forecast to warm to near to above-normal readings by Wednesday. Gusty Sundowner winds over southern Santa Barbara County are expected to begin late this afternoon and evening, and then peak for Tuesday into Wednesday. Cooler conditions are expected from the end of this week into the weekend, when there will be a slight chance of rain.
Short Term - Today through Thursday
Marine stratus over LA County earlier today has eroded, giving way to sunny skies areawide this afternoon. With shallow marine-layer depths (less than 1000 ft), and near-neutral pressure gradients turning offshore tonight, night and morning low clouds and fog appear to be unlikely through the middle of the week. The exception would be coastal LA County vicinity tonight and Tuesday morning, especially if an eddy were to form over the nearshore waters. And with the offshore gradients more substantially strengthening in response to surface ridging north of the area going forward early this week -- the trend toward offshore flow, warming temperatures, and gusty Sundowner winds is already initiating.
This pattern will facilitate more substantial warming for Tuesday and Wednesday, especially with modest midlevel height rises expected. Temperatures are forecast to be rising to near to above- normal readings Tuesday and Wednesday afternoons. By Wednesday, many locations are expected to experience their first above-normal high temperatures after 14 consecutive days. High temperatures Wednesday will by in the 80s and lower 90s in most areas, with mid 90s possible in some of the interior valleys, and then cooler closer to the coast and in the mountains. On Thursday, slight midlevel height falls within the southern extent of a longwave trough positioned over the western CONUS will result in temperatures falling around 5 degrees at most locations for highs.
Regarding the Sundowner winds -- even with the near-neutral pressure gradient thus far, gusts at Gaviota held in the 35-40-mph range for much of the morning. And with SBA-SMX and SBA-BFL offshore gradients strengthening to 2.5-3.5 mb tonight, confidence in gusts exceeding 45 mph has become high enough to start a Wind Advisory for SBA County SW Coast and the western Santa Ynez Range at 5PM this afternoon for the first round of Sundowner winds. Gusts of 45-55 mph will be possible in these areas through early morning Tuesday, before winds undergo typical diurnal weakening, temporarily. Then with these gradients strengthening in magnitude by another 1.0-1.5 mb Tuesday night into Wednesday, an expansion of strong northwest to northeast winds is expected. During those time periods, isolated gusts of 55-60 mph will be possible, especially in wind-prone areas around Gaviota and Refugio.
The Wind Advisory includes all three episodes of Sundowner winds (starting late afternoon each day Monday, Tuesday, and Wednesday), given short time durations between individual episodes. In addition, there is a 50-percent chance for eastward expansion of the Wind Advisory to account for more widespread strong winds -- potentially encompassing eastern parts of the Santa Ynez Mountains, SBA County SE Coast, and perhaps the I-5 corridor. Also of note, vertical cross sections indicate a low chance (20 percent probability) for mountain-wave development to bring even stronger wind gusts of 60-70 mph in spotty locations along the southern SBA coastal ranges and adjacent foothills including the Montecito area. Overall, the strongest winds are expected Tuesday into Wednesday, Sundowner winds those days will combine with a dry air mass to create potentially critical fire- weather conditions -- please reference the Fire Weather Watch for more details.
Long Term - Friday through Monday
A significant pattern shift is expected to close out the week, as a large and deep upper trough undergoes substantial amplification over the western CONUS. Deterministic/ensemble model guidance offer strong confidence in a deep low closing off over the central Great Basin, with much cooler air overspreading the area. This pattern favors strengthening onshore flow and a deepening marine layer late in the week and during next weekend. High temperatures could be 5-15 degrees below normal next weekend, perhaps even cooler. The increased cold advection will likely mitigate the development of marine stratus, however substantial cooling aloft will contribute to enough steepening in lapse rates to foster slight chances of showers Friday night into Sunday.
High confidence in the current forecast through Thursday, then moderate confidence thereafter. There is a moderate chance that winds could be stronger and seas much higher between Thursday and Saturday.
For the waters northwest through southwest of the Channel Islands, the chances for SCA (Small Craft Advisory) conditions will increase each day through Tuesday. A 50-70 percent chance of SCA (Small Craft Advisory) conditions by this afternoon and evening will increase to a 80-100 percent of widespread SCA (Small Craft Advisory) conditions by Tuesday afternoon. Widespread SCA (Small Craft Advisory) conditions with hazardous seas are virtually certain from Tuesday through Thursday. There is a 40-60 percent chance of Gale Force winds, especially during afternoon and evening hours. A Gale Watch is in effect from Tuesday afternoon through late Wednesday night. There is a moderate-to-high chance of SCA (Small Craft Advisory) conditions lingering into Friday and Saturday. Gales are possible again over the weekend.
For the nearshore waters along the Central Coast, winds and seas will generally remain below SCA (Small Craft Advisory) levels through early Tuesday. There is a 30-40 percent chance of SCA (Small Craft Advisory) level winds this afternoon and evening increasing to 80-90 percent chance by Tuesday afternoon. Widespread SCA (Small Craft Advisory) conditions are very likely to virtually certain between Tuesday and Thursday, especially during the afternoon and evening hours. There is a 20-30 percent chance for Gale Force winds Tuesday afternoon and evening, increasing to 40-50 Wednesday afternoon and evening. There is a moderate chance of SCA (Small Craft Advisory) conditions lingering into Friday and Saturday.
Inside the southern California bight, chances for SCA (Small Craft Advisory) level winds will increase to 60-80 percent this afternoon and evening. There is a 40-60 percent chance of widespread SCA (Small Craft Advisory) conditions (winds and seas) between Tuesday and Thursday. The highest chances are during the afternoon and evening hours across the western portion of the Santa Barbara Channel. Additionally for the Santa Barbara Channel a Gale Watch is in effect for Tuesday afternoon through late Wednesday night.
There is a 50 percent chance that high surf conditions develop between Tuesday evening and Thursday as a moderately long- period northwest swell building off the California coast. Surf will be the highest at west and northwest facing shores along the Central Coast. For theses beaches expect surf of 9 to 12 ft with local sets to 14 feet possible.
For Ventura County beaches, there is a 50 percent chance of elevated surf developing as soon as Tuesday evening and lasting through Thursday. For west and northwest facing beaches, expect surf of 4 to 6 feet with local sets to 7 feet possible.
Nuisance coastal flooding and minor beach erosion may occur Tuesday evening due to high surf for the Central Coast and Ventura County beaches.
NOAA Los Angeles/Oxnard CA Office: Watches - Warnings - Advisories
CA...High Surf Advisory in effect from 9pm this evening to 9 PM PDT Thursday for zones 340-346. (See LAXCFWLOX). Wind Advisory in effect until 5am PDT Thursday for zones 349-351.
Beach Hazards Statement in effect from 9pm PDT this evening through Thursday evening for zone 354. (See LAXCFWLOX). Fire Weather Watch in effect from Tuesday afternoon through late Wednesday night for zones 349>353. (See LAXRFWLOX). PZ...Small Craft Advisory in effect from 9am Tuesday to 3am PDT Thursday for zones 645-670.
Small Craft Advisory in effect until 3pm PDT Tuesday for zones 650-673-676.
Gale Watch in effect from Tuesday afternoon through late Wednesday night for zones 650-673-676.
Small Craft Advisory in effect until 3am PDT Tuesday for zone 655.