SLO County weather forecast: North County could reach the 80s as gusty winds hit the coast

Except for the sporadic thunderstorms, tranquil conditions with below-normal temperatures and primarily overcast skies have persisted along the Central Coast for the first half of June.

However, a significant change in the weather pattern will develop on Monday, Juneteenth, through this upcoming week as gale-force northwesterly winds return along the coastline, creating clearing skies during the late morning, afternoon and evening.

Sunday morning will see a deep marine layer with pockets of fog and mist, partially clearing during the afternoon as fresh and strong (19 to 31 mph) northwesterly winds develop. The marine layer will return Sunday night.

Sunday’s high temperatures will reach the high 70s in the inland valleys (Paso Robles) and the low 70s in the coastal valleys (San Luis Obispo). The beaches will warm up to the mid-60s, except the southerly facing beaches of Cayucos, Avila Beach and Shell Beach, which will warm to the low 70s.

A dry cold front will move through the Central Coast Sunday night and, combined with a 1,032-millibar Eastern Pacific High centered about 1,100 miles northwest of Central California, will create a steep pressure gradient along the coastline. Consequently, starting on Monday and continuing through this upcoming week, strong to gale-force (25 to 38 mph with gusts to 45 mph) northwesterly winds will develop during the late morning, afternoon and evening along the coastline. These northwesterly winds will help to mix out the temperature inversion layer, leaving behind clearing skies for much of the day.

By the end of this week, inland temperatures will reach the 80s, and the coastal valley and the southerly facing beaches of Cayucos, Avila Beach and Shell Beach will be in the mid-70s. The rest of the coastline will remain in the 60s.

The long-range models do not indicate any rain for the Central Coast through the end of June.

Surf report

Increasing northwesterly winds along the coastline will generate a pattern of 6- to 8-foot northwesterly (310-degree, deep-water) sea and swell (with a 5- to 8-second period) during the afternoon and night, decreasing to 5 to 7 feet during the morning. This pattern will start Sunday and will continue through this upcoming week.

Combined with this northwesterly sea and swell will be 1- to 2-foot southern hemisphere (200-degree, deep-water) swell (with a 14- to 16-second period) on Sunday through Friday.

Seawater temperatures will range between 56 and 59 degrees through Sunday, decreasing to 53 to 55 degrees on Monday through next Sunday as upwelling increases.

This week’s temperatures

LOWS AND HIGHS, PASO ROBLES

LOWS AND HIGHS, SAN LUIS OBISPO AND COASTAL VALLEYS

John Lindsey is a retired PG&E marine meteorologist. Email him at JohnLindseyLosOsos@gmail.com or follow him on Twitter @PGE_John.