More rain is headed to SLO County this week. Here’s how much and where

Most of January has seen well below-average precipitation along the Central Coast as the Eastern Pacific High off the California coast has forced the storm track into the Pacific Northwest.

However, since Friday, this area of high pressure has shifted to the southwest, opening the storm door for Central California. A series of low-pressure systems will tap into a plume of subtropical moisture.

This will result in the development of periods of fresh to strong (19 to 31 mph) southerly winds with each passing front, gentle to moderate rainfall, rising southerly seas and warmer seawater temperatures. In fact, seawater temperatures could reach the low 60s by Tuesday.

Fresh to strong (19 to 31 mph) southerly winds and rain were forecast on Saturday into Sunday morning. The southerly winds were forecasted to decrease, and rain was expected to turn to scattered showers on Sunday afternoon.

Temperatures will be mild, with highs reaching the low 60s throughout the region with overnight lows dropping to the high 40s in the inland valleys (Paso Robles) and mid-50s in the coastal valleys (San Luis Obispo) and along the beaches.

Another low-pressure system will produce fresh to strong (19 to 31 mph) southerly winds and rain Sunday night into Monday.

Due to the subtropical nature of this system, temperatures will remain mild, with snow levels above 7,000 feet. A few rain showers are forecasted for Tuesday morning, ending by Tuesday afternoon. From one to three inches of rain is expected from Saturday through Tuesday morning, with higher amounts in the Santa Lucia Mountains.

Fresh to strong (19 to 31 mph) northwesterly winds and marine low clouds along the coastline are forecast on Tuesday afternoon and night.

A pattern of moderate to fresh (13 to 24 mph) Santa Lucia (northeasterly) winds during the night and morning, decreasing and shifting out of the northwest during the afternoon, will start on Wednesday and continue through Saturday.

This pattern will produce warmer temperatures and clear to partly cloudy skies, except for pockets of low marine clouds that will hug the coastline during the evening and pockets of dense morning fog in the inland valleys.

Temperatures could reach the low 70s by Saturday and Sunday.

Surf report

A 7- to 9-foot westerly (270-degree, deep-water) swell (with an 11- to 14-second period) is forecast along our coastline on Sunday, decreasing to 5 to 7 feet on Monday. Combined with this northwesterly swell will be 3- to 5-foot (180-degree, shallow-water) seas on Sunday into Monday.

A 6- to 8-foot west-northwesterly (285-degree, deep-water) swell (with an 18- to 20-second period) will arrive on Tuesday, building to 8 to 10 feet (with a 15- to 17-second period) on Wednesday and remaining at this height and period through Friday.

Seawater temperatures will range between 56 and 58 degrees through Monday, increasing to 58 to 61 degrees on Tuesday into 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 21, 2024 at 5:00 AM.