SLO County weather: Seasonal temperatures return along with fog at the coasts

Last week gusty Santa Lucia (northeasterly) winds produced record-breaking high temperatures throughout the Central Coast and mostly clear skies, except for variable amounts of smoke. This week persistent northwesterly (onshore) winds will create near seasonal temperatures and marine low clouds with areas of night and morning mist and fog in the coastal regions.

The ridge of high pressure over California responsible for the gusty Santa Lucia winds and record- breaking temperatures will gradually weaken over the next 72-hours.

The winds will shift out of the northwest along the coastline on Sunday and will remain onshore through this week. This condition will allow the marine layer to return along the immediate coastline as early as Sunday night and will create mist and fog during the night and morning and cooler temperatures.

The marine layer is expected to deepen and move farther inland on Tuesday into Friday. Over this period, high temperatures will slowly cool to the high-80s in the inland valleys (Paso Robles), 70s in the coastal valleys (San Luis Obispo) and 60s along the beaches.

A few of the ensemble packages are advertising a chance of some rain showers developing toward the end of October into early November around the Halloween time frame. Remember, these are long-range models and will undoubtedly change, but we can certainly hope.

Surf report

Sunday’s 3- to 5-foot northwesterly (300-degree, deep-water) swell (with an 8- to 11-second period) will increase to 4 to 6 feet with the same period on Monday afternoon and will remain at this level through Saturday. Arriving from the Southern Hemisphere: A 1- to 3-foot Southern Hemisphere (185-degree, deep-water) swell (with an 18- to 20-second period) will arrive along our coastline on Tuesday into Wednesday.

Seawater temperatures will range between 56 and 59 degrees through Monday, increasing 57 to 61 degrees 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

Areas of dense morning fog could develop in the coastal regions. If you are driving in foggy conditions keep your lights on low beam.

High beams will reflect off the fog, creating a “white wall” effect and reduce your speed. Fog creates a visual illusion of slow motion when you might actually be speeding.

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.