A powerful winter swell is headed for the Central Coast, bringing with it dangerously high surf and the potential for coastal flooding. A High Surf Advisory in effect from 2 AM Saturday to 1 AM Sunday, followed by a High Surf Warning from 1 AM Sunday to noon PST Tuesday.
Wave heights are expected to build throughout the weekend, reaching 10 to 15 feet on Saturday and increasing to 15 to 20 feet on Sunday. By Monday afternoon, waves could reach a staggering 18 to 25 feet, particularly on west to northwest facing shores. These powerful waves will be accompanied by very dangerous rip currents.
Impacts:
- Exceptional risk of ocean drowning: The strong currents and powerful waves can easily sweep people off their feet and pull them out to sea.
- Damage to coastal structures: Piers, jetties, and other coastal infrastructure could be damaged by the force of the waves.
- Coastal flooding: High tides between 4.0 and 5.0 feet are expected each morning between 3 and 6 AM, increasing the risk of coastal flooding, especially in low-lying areas like the Oceano Dunes. Beach roads and parking lots could be inundated with water. The risk for coastal flooding is highest Monday night through Tuesday.
Precautionary/Preparedness Actions:
- Stay out of the water: The ocean will be extremely dangerous this weekend. Even experienced swimmers and surfers are at risk.
Tonight and Saturday:
A shallow marine layer, combined with very light winds and clear skies, will result in dense fog formation along coastal areas during the night and early morning hours. Fog could reduce visibility significantly, particularly along Highway 1 and near the beaches. High clouds might limit fog development slightly, but areas of fog are still likely.
Saturday Afternoon to Sunday Morning:
A weak Pacific system will graze the northern Central Coast, bringing a chance for light rain mainly to northern San Luis Obispo County. Rainfall amounts will be minor, likely under 0.10 inches, and unlikely to extend into Santa Barbara County.
Key Factors:
- A persistent ridge over the northern Rockies is deflecting stronger storm systems, leaving only weaker systems to impact the Central Coast.
- Inland areas remain dry and warm as the ridge suppresses significant weather activity.
- Rainfall Expectation:
- San Luis Obispo County (Northwest areas): Up to 0.10 inches.
- Santa Barbara County: Dry.
Sunday:
Dry conditions will dominate as the weak system exits. Morning fog will likely redevelop along the coast, with slow clearing. Inland areas will warm considerably under strengthening high pressure.
- Temperatures:
- Coastal areas: Mid-60s to upper 60s.
- Inland areas: near 70.
Monday:
The warm-up continues, especially inland, as high pressure strengthens. Offshore trends may develop slightly, reducing coastal fog and keeping temperatures mild near the coast. Expect more sunshine inland and continued calm weather.
- Highs:
- Coastal areas: Upper 60s.
- Inland valleys: Upper 60s.
Long-Term Forecast (Tuesday through Friday):
Tuesday:
A more substantial Pacific storm system is expected to move into the region. While the system’s core energy will remain focused to the north, it has a better chance of bringing light rain southward into Santa Barbara County. The northern part of San Luis Obispo County will likely see the highest rainfall totals.
- Rainfall Projections:
- Northwest San Luis Obispo County: up to .50".
- Most of SLO county up to .20"
- Santa Barbara County: Up to 0.10 inches, with lower chances south of Point Conception.
Wednesday:
The system will quickly move east, leaving behind partly cloudy skies and cooler temperatures. Winds could increase behind the storm, especially in the north-south oriented valleys and passes, where a strong northerly flow may develop.
Thursday and Friday:
A return to dry conditions with above-normal temperatures inland. Coastal areas will remain cooler with possible morning fog. The weather pattern remains dominated by the ridge, preventing any significant storms from reaching the area through the end of the week.
