What’s in store for SLO County weather this week? See latest forecast

Strengthening northwesterly winds along the coast will help clear skies by late morning and afternoon, while an upper-level high over the Desert Southwest will bring warmer temperatures — especially to the inland valleys throughout the week.

A pattern of strong to gale-force (25 to 38 mph) northwesterly winds will develop along the coastline from late morning through evening, easing overnight. These winds will allow low marine clouds — along with pockets of fog, mist, and drizzle — to push into the coastal valleys during the overnight.

Meanwhile, inland valleys should remain mostly clear, as the marine layer stays thin and compressed under the influence of an upper-level high.

Afternoon winds will be strong enough to clear the marine layer later each morning, resulting in mostly sunny skies with occasional patches of mid- to high-level clouds from intermittent surges of subtropical moisture moving in from the southeast.

High temperatures in the inland valleys (Paso Robles) will reach the low to mid-90 sthrough Thursday, rising to the low 100s Friday, Saturday and next Sunday. The coastal valleys (San Luis Obispo) will range from the low to mid-70s through Tuesday, warming into the 80s Wednesday through the weekend. Beach temperatures will stay in the mid to upper 60s, except at south-facing beaches like Cayucos, Avila Beach, and Shell Beach, where highs could reach the upper 70s.

Looking ahead to the following week, the upper-level high is expected to shift further east, allowing increased subtropical moisture to flow into California.

This will bring a chance of rain showers and thunderstorms, particularly over the Sierra Nevada and the higher elevations of eastern San Luis Obispo and Santa Barbara counties.

Surf report

Strong to gale-force (25 to 38 mph) northwesterly winds along the California Coastlin ewill generate a 6- to 8-foot northwesterly (300-degree deep-water) sea and swell (with a 7- to 11-second period) through Monday, decreasing to 4- to 8-feet with the same period on Tuesday through Saturday.

Arriving from the Southern Hemisphere:

A 1- to 2-foot southern hemisphere (205-degree deep water) swell (with a 15- to 17 -second period) will arrive along our coastline on Wednesday and will remain at this level through Friday, gradually fading away over the weekend.

Seawater temperatures:

Surface seawater temperatures will range between 54 and 56 degrees through Monday ,decreasing to 52 to 54 degrees on Tursday through next Sunday.

On this date in Weather History (Aug. 3):

1970: Hurricane Celia struck the coast of Texas producing wind gusts to 161 mph at Corpus Christi, and estimated wind gusts of 180 mph at Arkansas Pass. The hurricane was the most destructive of record along the Texas coast causing $454 million in damage and also claimed 11 lives. (David Ludlum)

2010: The largest hailstone on record in the United States fell in Vivian, South Dakota. It was 8 inches in diameter, over 18 inches in circumference and weighed almost 2 pounds. Initial estimates were that the updrafts necessary for a hailstone of this size would have exceeded 160 mph. (Jan Null)

2017: A surge of monsoonal moisture triggered widespread thunderstorms and rain showers across the Central Coast. The Diablo Canyon rain gauge recorded 0.08 inches of rainfall, while nearby Davis Peak measured 0.12 inches. The Upper Toro rain gauge, located off Highway 41 between Morro Bay and Atascadero, reported a more substantial 0.35 inches. According to SLOWeather.com, over 2,500 lightning strikes were detected across the region. The influx of subtropical moisture also brought warm, muggy overnight conditions, with elevated dew points. Paso Robles Airport recorded a low of 71 degrees, while Bakersfield didn’t drop below a sweltering 87 degrees — more typical of a summer night in Florida.

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 X @PGE_John.