SLO County weather forecast for week of Sept. 26: Overcast skies and winds, then heat

Variable amounts of smoke and haze, mostly above 6,000 feet of altitude, is forecast to continue to stream over the Central Coast from the wildfires burning in the central and southern Sierra Nevada through Monday.

Gentle southerly to northwesterly (onshore) winds and mostly overcast skies along the beaches with pockets of night and morning fog and drizzle will continue through Sunday. Over this time frame, high temperatures along the shoreline will range from the high 50s to the mid-60s.

Away from the ocean, the marine layer will clear from the coastal valleys by late Sunday morning. Temperatures in the coastal valleys (San Luis Obispo) will range between the low to mid-70s. The inland valleys will warm to the mid-80s with Paso Robles reaching 87 degrees on Sunday.

A Gulf of Alaska storm and associated cold front is forecast to produce mid- to high-level clouds and increasing northwesterly winds starting on Monday afternoon and continuing through Wednesday. These northwesterly winds along the coastline will peak on Tuesday at moderate gale-force to fresh gale-force (32 to 46 mph) levels. These winds will mix out the temperature inversion layer, leaving mostly clear skies behind.

A warming trend is forecast to start next Friday, Oct. 1, as high pressure builds into Central California and Santa Lucia (northeasterly) winds develop during night and morning. The long-range models are still not indicating any rain for the Central Coast.

Surf report

Sunday’s 4- to 6-foot northwesterly (295-degree, deep-water) swell (with an 8- to 16-second period) is expected to continue at this level through Monday morning.

Increasing northwesterly along the Northern and Central California will generate a 4- to 6-foot northwesterly (310-degree, deep-water) sea and swell (with a 5- to 13-second period) along our coastline on Monday afternoon and night. This northwesterly sea and swell will build to 9- to 11-(with a 7- to 15-second period) along our coastline on Tuesday into Wednesday decreasing to 4 to 6 feet (with an 8- to 12-second period) on Thursday through Friday.

Seawater temperatures will range between 57 and 60 degrees on Sunday through Monday. Seawater temperatures will decrease to 51 to 55 degrees on Tuesday through Friday.

This week’s temperatures

LOWS AND HIGHS, PASO ROBLES

LOWS AND HIGHS, SAN LUIS OBISPO AND COASTAL VALLEYS

PG&E safety tip

With oak trees heavily burdened with acorns and stressed from well below-average rain last season, fallen limbs and other debris is expected with Tuesday and Wednesday’s wind event. Never touch downed power lines.

Stay away from the lines and keep others away from them. Call 911 immediately to report the location of a downed line. After reporting the downed line, call Pacific Gas and Electric Co. toll-free at 800-743-5000.

John Lindsey’s is PG&E’s Diablo Canyon marine meteorologist and a media relations representative. Email him at pgeweather@pge.com or follow him on Twitter @PGE_John.

This story was originally published September 26, 2021 at 5:00 AM.