Sizzling hot temperatures continue for inland SLO County. Here’s the forecast for the week

The timeless Central Coast summer weather pattern of low marine clouds with pockets of fog and mist during the night and morning, partially clearing during the afternoon along the coastline with warm temperatures in the coastal valleys and sizzling hot temperatures in the inland valleys will continue through Sunday.

With that said, a change in this pattern is expected on Monday as a slug of subtropical moisture streams northward over our area, followed by gale-force northwesterly winds and clearing skies along the coastline during the late morning and afternoon on Tuesday through Saturday.

A shallow marine layer will continue to hug the coastline on Sunday, keeping temperatures mainly in the high-50s along the beaches. The coastal valleys (San Luis Obispo) will see clear skies with afternoon highs in the low-80s, while the inland areas (Paso Robles/Mid-State Fair) will range between 101 and 104 degrees on Sunday.

The models indicate variable amounts of subtropical moisture will stream northward over the Central Coast from Mexico. This condition will produce scattered mid- to high-level clouds, creating slightly cooler temperatures but higher humidity levels, which will make it feel warmer on Monday.

In response to a steep pressure gradient along the Northern and Central California coastline, strong to gale-force (25 to 38 mph) northwesterly winds will develop during the late morning and afternoon along the San Luis Obispo County coastline on Tuesday through Saturday.

These winds will help to mix out the temperature inversion/marine layer during the late morning and afternoon, leaving behind sunny skies.

Consequently, temperatures along the southerly facing beaches of Cayucos, Avila, and Shell Beach will reach the 70s, while Cambria, Morro Bay, Los Osos and Pismo Beach will warm to the 60s.

The coastal valleys will reach the high 70s, maybe even the low 80s during the late morning before cooling during the afternoon, while the inland valleys will hit the high 90s during the final week of the Mid-State Fair. These winds will bring cooler marine air to the fair during the overnight, allowing the temperatures to drop to the 50s, so being a sweater or jacket if you’re attending the night-time shows.

There’s still no indication of any Santa Lucia (northeasterly) winds developing in the future; hence, it will remain cool to mild in the coastal regions. A few of the models are advertising that monsoon moisture could move over the Central Coast during the first week of August.

Surf report

Strong to gale-force (25 to 38 mph) northwesterly winds will generate a 5- to 7-foot northwesterly (300-degree, deep-water) sea and swell (with a 5- to 9-second period) along our coastline on Sunday through Saturday, July 29.

Combined with this northwesterly sea and swell will be 1- to 2-foot southern hemisphere (210-degree, deep-water) swell (with a 15- to 17-second period) on Thursday through Saturday.

Seawater temperatures will range between 54 and 57 degrees through Monday, decreasing to 53 to 55 degrees on Tuesday and will remain at this level through Saturday.

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.