Heavy rain, strong winds expected to hit SLO County through this week

The Paso Robles Municipal Airport has recorded 7.9 inches of precipitation this rain season.

Historically, the airport normally records 4.5 inches by Jan. 7. Cal Poly (home of climatology for San Luis Obispo) has seen 17.9 inches or about 210% of average rainfall.

These percentages will significantly increase this week as a series of low-pressure systems will produce southerly gales, moderate to heavy rain, and chaotic oceanographic conditions as the storm door remains wide open for the Central Coast.

A cold front will move through the Central Coast on Sunday morning with strong to gale-force (25 to 38 mph) southerly winds and moderate to heavy rain. Total rainfall amounts will range between 0.75 and 1.5 inches with higher amounts in the Santa Lucia mountains.

Temperatures will remain mild, with the inland valleys (Paso Robles) dropping to the mid-40s while the coastal valleys (San Luis Obispo) are in the high-40s. Daytime highs will range between the high-50s to the low-60s throughout the Central Coast.

A 993 millibar low-pressure system off the Central California coastline and associated warm and cold fronts will produce moderate gale-force to fresh gale-force (32 to 46 mph with gusts to 60 mph), southerly winds, moderate to heavy rain (3 to 5 inches with higher amounts in the Santa Lucia mountains), and extremely high southerly seas (14 to 16 feet) on Monday into Tuesday.

A break in the weather is forecast on Wednesday through Friday before another low-pressure system produces southerly winds, rain and high westerly swell next Saturday and Sunday.

Surf report

Like last week, a series of storms will generate rough oceanographic conditions this week.

A 9- to 11-foot westerly (270-degree, deep-water) swell (with an 11- to 15-second period) is expected along our coastline on Sunday.

Increasing southerly winds will generate 14- to 16-foot southerly (200-degree, shallow-water) seas on Monday into Tuesday, followed by a 10- to 12-foot westerly (275-degree, deep-water) swell (with an 8- to 14-second period) on Wednesday.

A 15- to 17-foot westerly (270-degree, deep-water) swell (with an 18- to 20-second period) is expected along our coastline on Thursday into Friday.

Seawater temperatures will range between 57 and 59 degrees through Friday.

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.

This story was originally published January 8, 2023 at 5:30 AM.