Point Piedras Blancas to Santa Cruz Island CA between 60 and 150 NM Offshore Forecast
|Tonight...N Winds 10 To 15 Kt, Becoming 10 To 20 Kt. Seas 5 To 7 Ft.|
|Wed...N Winds 10 To 20 Kt. Seas 5 To 7 Ft.|
|Wed Night...N To Nw Winds 15 To 25 Kt. Seas 4 To 8 Ft.|
|Thu...N To Nw Winds 15 To 25 Kt. Seas 6 To 10 Ft.|
|Thu Night...Nw Winds 15 To 25 Kt, Becoming N. Seas 9 To 13 Ft.|
|Fri...N To Nw Winds 15 To 25 Kt. Seas 11 To 13 Ft.|
|Fri Night...N To Nw Winds 15 To 25 Kt. Seas 10 To 12 Ft.|
|Sat...N Winds 15 To 25 Kt. Seas 9 To 11 Ft.|
|Sat Night...N Winds 15 To 25 Kt. Seas 8 To 11 Ft.|
|Sun...N To Nw Winds 5 To 15 Kt. Seas 7 To 9 Ft.|
|Sun Night...N Winds 5 To 15 Kt. Seas 6 To 8 Ft.|
| Area Forecast Discussion|
National Weather Service Los Angeles/Oxnard CA
821pm PDT Tuesday September 22 2020
Ridging aloft will build in through Thursday and bring a slight warm-up. Temperatures will remain above normal into the weekend, then a significant warming trend is forecast for early next week as high pressure aloft strengthens and becomes the dominant weather feature across the area. Night through morning low clouds and fog will become more confined to the coast over the next several days.
.SHORT TERM (TUE-FRI)...22/820 PM.
Satellite imagery showing low clouds and fog moving into the Central Coast this evening, along with patches developing across the Ventura and southern Santa Barbara coasts. 00z Vandenberg sounding and ACARS data out of LAX showing the marine layer depth around 1000 feet this evening. With an upper level ridge of high pressure building over Southwest California overnight, the marine layer depth will continue to shrink, bring an increased threat for patchy dense fog, especially across the Central Coast where a dense fog advisory may be needed. Any low clouds and fog that develop tonight into Wednesday morning are generally expected to remain confined to the coastal plain.
The upper level ridge of high pressure combined with a slight weakening of the onshore pressure gradients will also likely bring a few degrees of warming across most areas on Wednesday. Have bumped up temperatures a few degrees for tomorrow in evening update as temperatures climbed a bit higher today than expected.
*** From previous discussion ***
The building high will help boost temps a few more degrees Wed/Thu but nothing significant. Temps will jump back up a few degrees above normal but nothing too unusual for this time of year. The trends will briefly reverse Fri as a trough passes through the Pac NW but just minor cooling at best. Some northerly winds expected in southern SB County each evening starting Wednesday but so far models are keeping wind speeds mostly below advisory levels. Marine layer clouds will likely be confined to LA and possibly Ventura County with the increase in northerly flow Wed/Thu.
.LONG TERM (SAT-TUE)...22/154 PM.
An even stronger ridge will start to build over the West Coast Saturday but not really kick into gear until early next week, though even then temps aren't expected to come anywhere close to the earlier heat wave that saw highs well above 110 in the coastal valleys. There are a few extreme ensemble solutions suggesting a hotter scenario than currently expected but not too much support for that now. Inland areas will see a little warming Saturday but then all areas will start warming Sunday as a 595 high sits almost on top of us. Warmer valley temps expected to reach triple digits by Sunday with the warmest days likely to be Mon/Tue. Record highs are quite high through Monday. The 27th is the anniversary of the all time Downtown LA high of 113 and the records for Monday are only a few degrees lower so Tuesday would probably be our best chance for record highs but even then it would be a stretch unless some of the minority become more favored in subsequent model runs.
For the waters southwest through north of the Channel Islands and outside the southern California, winds will increase through Wednesday evening, spreading south to near San Nicolas Island and east into near shore waters along the Central Coast. Small Craft Advisory (SCA) level winds across the far northwest portion of the coastal waters this evening will spread southward into Wednesday. There is a chance of gales between Thursday night and early Saturday morning. SCA (Small Craft Advisory) conditions will likely develop across much of the waters west of the southern California bight and more than 10 NM offshore of the Central Coast. A moderately long-period northwest swell building across the outer coastal waters will contribute to SCA (Small Craft Advisory) conditions between Thursday evening and Saturday evening.
Inside the southern California bight, winds and seas will remain below SCA (Small Craft Advisory) levels. There is a 30-40% chance that SCA (Small Craft Advisory) level winds may develop across the western portion of the Santa Barbara Channel Wednesday through Friday.
Patchy dense fog from a shallow marine layer could create hazards to mariners tonight through Wednesday.
.LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect until 3am PDT Thursday for zone 670. (See LAXMWWLOX).
.HAZARD POTENTIAL OUTLOOK (FRI-TUE).
Strong high pressure is expected to build over the West Coast Sunday and Monday. Heat stress and elevated fire weather conditions will be possible, especially on Monday.