SLO County weather forecast for the week of June 27: Hot, sunny and a chance for rain

An upper-level low-pressure system off Monterey Bay last week produced sunny and warmer temperatures along the beaches. At the same time, the coastal and inland valleys remain mild.

This week, high pressure will build overhead and will produce triple-digit readings away from the ocean. Paso Robles is forecast to reach 107 degrees on Sunday. The record daily high on Sunday, June 27 at the Paso Robles Airport is 110 degrees set back in 1956.

Closer to the ocean, night and morning marine low clouds with areas of fog and mist will develop during the night and morning. The coastal valleys (San Luis Obispo) are expected to reach the mid-80s.

Along the coastline, strong to gale-force (25 to 38 mph) afternoon northwesterly winds will keep the beaches in the 60s, except for Cayucos, Avila Beach, and Shell Beach, which will hit the low 80s.

Temperatures will subside slightly on Monday. The northwesterly winds will decrease and will shift out of the south on Tuesday.

This condition will allow the marine layer to deepen as the upper-level ridge breaks down; in fact, the beaches will remain overcast throughout the day, resulting in cooler temperatures in the coastal regions.

An approaching low-pressure system later Wednesday into Thursday may bring monsoonal moisture to the Central Coast, resulting in increased cloud cover and higher humidity levels.

A few of the weather models are indicating a chance of rain showers or thunderstorms by Thursday.

The long-range models indicate little change in temperatures over the latter half of this week, with daytime highs generally remaining around seasonal to slightly above- average levels through the 4th of July.

However, the marine layer with areas of fog and mist is expected to return to the coastline.

Surf report

Increasing northwesterly winds along the California coastline will generate a 5- to 7-foot northwesterly (310-degree, deep-water) sea and swell (with a 5- to 11-second period) on Sunday through Monday, decreasing to 4 to 6 feet by Tuesday. A 3- to 5-foot northwesterly (290-degree, deep-water) swell (with an 8- to 11-second period) is forecast on Wednesday into Friday.

Seawater temperatures will range between 54- and 57-degrees through Saturday.

This week’s temperatures

LOWS AND HIGHS, PASO ROBLES

LOWS AND HIGHS, SAN LUIS OBISPO AND COASTAL VALLEYS

PG&E safety tip

All thunderstorms produce lightning. Lightning kills 20 or more people in the United States each year, and hundreds more are severely injured. Remember, “When thunder roars, go indoors!”

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.