Point Piedras Blancas to Point Sal from 10 to 60 NM Marine Forecast
|Today...Nw Winds 10 To 15 Kt. Wind Waves 2 Ft Or Less. Mixed Swell Nw 3 Ft At 8 Seconds And S 2 Ft At 16 Seconds. Patchy Dense Fog With Vsby 1 Nm Or Less In The Morning. Vsby 1 Nm Or Less In The Morning.|
|Tonight...Nw Winds 15 To 20 Kt In The Evening, Becoming 10 To 15 Kt. Wind Waves 2 To 3 Ft. Nw Swell 4 Ft At 7 Seconds. Patchy Dense Fog With Vsby 1 Nm Or Less After Midnight.|
|Mon...Nw Winds 15 To 20 Kt With Gusts To 25 Kt. Combined Seas 4 To 5 Ft Dominant Period 7 Seconds. Patchy Dense Fog With Vsby 1 Nm Or Less In The Morning.|
|Mon Night...Nw Winds 15 To 20 Kt With Gusts To 25 Kt. Combined Seas 4 To 5 Ft Dominant Period 7 Seconds. Patchy Fog.|
|Tue...Nw Winds 15 To 20 Kt With Gusts To 25 Kt. Combined Seas 5 To 6 Ft Dominant Period 7 Seconds. Patchy Fog In The Morning.|
|Tue Night...Nw Winds 20 To 30 Kt. Combined Seas 6 To 7 Ft Dominant Period 7 Seconds. Patchy Fog After Midnight.|
|Wed...Nw Winds 15 To 25 Kt. Combined Seas 6 To 7 Ft. Patchy Fog.|
|Thu...Nw Winds 15 To 25 Kt. Combined Seas 6 To 7 Ft. Patchy Fog.|
| Area Forecast Discussion|
National Weather Service Los Angeles/Oxnard CA
1226pm PDT Sunday September 25 2022
Ridging aloft and an associated heatwave will peak early this week before broad troughing and cooler conditions build into the region heading into next weekend. Night to morning clouds may become sparse early next week before potentially becoming widespread later in the week.
Short Term - Today through Tuesday
Current satellite and surface observations indicate some stratus and fog across the Central Coast and along the Ventura coast. Additionally, some scattered high clouds are drifting over Santa Barbara and San Luis Obispo counties. Current sounding data indicates marine inversion is around 700-1000 feet deep. Some locally gusty north winds (gusts around 30 MPH) are observed across the western Santa Ynez Range.
For the morning, only have made one noticeable adjustment to the immediate forecast. Looking at high resolution models (SREF, HRRR, CAM, etc), most develop some isolated echoes over the San Gabriel Mountains and around the Mount Pinos area this afternoon. Instability looks good and PWATs (Precipitable Waters) are about 0.75-1.00 inches this afternoon. So, there is some chance of thunderstorms this afternoon and have increase POPs to around 15% this afternoon and early evening. If thunderstorms do develop, they will be isolated and likely to produce little appreciable rainfall. So, gusty outflow winds and dry lightning will be main concerns.
Otherwise, forecast for the immediate short term looks good. For the afternoon forecast suite, will need to watch the potential for some low-end advisory-level Sundowners across the western Santa Ynez Range this evening (as gradients strengthen). Also, will need to look closer at the heat products for Monday - Wednesday
models seems to be trending down with heat intensity.
***From Previous Discussion***
The latest satellite showed the Central Coast to Santa Ynez Valley socked in with low clouds with low clouds and fog filling in across portions of the Santa Barbara South Coast to Ventura coast. Temperatures are up 2-5 degrees from 24 hours ago, sure signs that the promised heat is on the way.
Weak offshore trends today and similar if not slightly stronger ridging aloft will bring another 2-4 degrees of warming today with the hottest valleys to interior 95-102 except locally 105. Despite the warmup, we fall shy of heat advisory thresholds across the region. However, this is just the beginning. Monday and Tuesday are still shaping up to be the hottest days, with many areas another couple of degrees warmer with both daytime highs and overnight lows. Warmest valley to interior areas will top out 100-105. Latest ensemble guidance reduces confidence for how hot it will get along the immediate coast of Los Angeles and Ventura Counties as marine influence may be more stubborn than anticipated. Will hang onto Heat Advisories there for given how sensitive coastal communities can be to heat with many not having access to air conditioning. Relatively meager offshore trends could also flip heat trends once again. Interior coastal areas and especially Valleys are looking good for Advisory to Warning level heat during the period. A few additional Heat Advisories may be need along the fringe of the current products, with the Los Angeles mountains and Santa Barbara County away from the Central Coast also in play.
Some subtropical mid-level moisture streaming in from the southwest will probably support cumulus buildups across the eastern San Gabriels and Ventura mountains today and possibly into early next week, with a small (5-10 percent chance) of a shower or thunderstorm developing. Dry low level and moderate instability could support a dry lightning or gusty winds should a thunderstorm manage to form.
Height falls associated with a trough passing to the north and offshore trends should bring some cooling to interior areas Wednesday, with some warming possible for coastal areas. Overnight to morning low clouds and fog may become more widespread, especially if an eddy spins up.
Winds will generally be light through the period, save for gusty Sundowner winds possibly approaching advisory levels for southwest Santa Barbara County. The local offshore flow may boost daytime highs into the low to even mid 90s for foothill locals Monday or Tuesday evening. Hence the aforementioned potential need for heat products in the region.
Long Term - Wednesday through Saturday
Good ensemble (GEFS ECS GEPS) consensus and run to run consistency through Friday provides above normal confidence that broad southwest flow will develop atop the region, with increased onshore flow and lower 500 mb heigheights aloft bringing much cooler conditions for most by Thursday. As is often the case in this type of set up, interior and perhaps immediate coastal areas may be slowest to see significant cooling. In any case, no heat products should be needed from Thursday on.
Lower forecast confidence exists heading into next weekend as ensemble guidance is having trouble handling a trough passing well to our north. This is probably of little consequence as weather should be quiet regardless of the eventual outcome. Forecast temperatures could easily be off by 5 degrees depending on the timing and strength of the trough. For example, while forecast temperatures are generally in the 70s and 80s, the warm end of guidance (10-20 percent chance) peaks in the 80s to 90s for many areas. The extent and coverage of night to morning stratus and fog will likewise be dependent on eventual trough evolution, with the Central Coast having the greatest odds.
No changes to the marine forecast in the morning update, other than to lighten the winds in the southern inner waters during the late night/early morning hours, to promote more of a diurnal cycle in wind speeds.
By late this afternoon, moderate to high confidence in Small Craft Advisory (SCA) level NW winds developing from Point Conception to San Nicolas Island. There is a 30% chance of the SCA level winds spreading into the southern and western portion of the Santa Barbara Channel and the nearshore waters from Point Mugu to Santa Monica this afternoon and evening. Then by Monday, gusty winds will become more widespread and SCA (Small Craft Advisory) level winds are likely from the Central Coast to San Nicolas Island.
NOAA Los Angeles/Oxnard CA Office: Watches - Warnings - Advisories
Excessive Heat Warning... effect from 10am Monday to 8 PM PDT Tuesday for zones 88-365-547-548.
Heat Advisory in effect from 10am Monday to 8pm PDT Tuesday for zones 356>359-363.
PZ...Small Craft Advisory in effect until 2am PDT Tuesday for zones 673-676.