Series of storms could bring up to 5 inches of rain to SLO County

Break out the umbrellas.

After several weeks of “Chamber of Commerce” weather with clear and warm afternoons, a significant change in the weather pattern will develop this week as a series of storms marches across the Pacific and slams into California, producing gusty southerly winds and rain starting Sunday evening and continuing through Saturday.

A storm off the coast of California will produce gentle to moderate (8 to 18 mph) southerly winds and increasing clouds on Sunday afternoon, with scattered rain showers developing Sunday evening into Sunday night as the associated cold front approaches the Central Coast.

The southerly winds will increase to fresh to strong (19 to 31 mph) levels, and steady rain is expected Monday as the cold front moves through the region. Total rainfall on Monday should range between 0.33 and 1.00 inches.

Temperatures will be relatively mild, with overnight lows in the 50s and daytime highs in the 60s as the cold front taps into subtropical moisture. Snow levels will remain above 8,000 feet.

Another storm will approach San Luis Obispo and Santa Barbara counties on Tuesday, producing strong to gale-force (25 to 38 mph) southerly winds and rain. Total rainfall on Tuesday should range between 0.50 and 0.75 of an inch.

The associated cold front will move through our area on Wednesday with moderate gale-force to fresh gale-force (32 to 46 mph) southerly winds and periods of heavy rain. Total rainfall on Wednesday is expected to range between 1.5 and 2.5 inches, with heavier amounts in the Santa Lucia mountains.

Like the previous low-pressure system, temperatures will remain mild, with snow above 7,500 feet.

The last in this series of storms will arrive on Thursday into Saturday with strong to gale-force (25 to 38 mph) southerly winds and even more rain. Total rainfall over this period should range from 0.50 to 1.5 inches. This system will be cooler, with daytime temperatures dropping to the 50s and snow levels lowering to around 6,000 feet.

Altogether, total rainfall amounts from Sunday to Saturday should range between 3 to 5 inches, with more significant amounts in the Santa Lucia mountains above Cambria.

A break in the weather is expected on Sunday through Christmas, with an unsettled weather pattern developing by the middle part of next week.

Surf report

A 6- to 8-foot southwesterly (245-degree, deep-water) swell (with an 11- to 17-second period) is forecast along our coastline on Sunday.

Increasing southerly winds along the Northern and Central California coastline will generate a 5- to 7-foot southerly (200-degree, deep-water) sea and swell (with a 5- to 14-second period) Monday through Tuesday, building to 9 to 11 feet on Wednesday into Thursday.

A 5- to 7-foot westerly (270-degree, deep-water) swell (with an 8- to 11-second period) is forecast along our coastline on Friday into Saturday.

Seawater temperatures will range between 59 and 62 degrees 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.