Bundle up, SLO County: Cold weather, possible thunderstorms expected this week

You should reconsider if you’re thinking about stowing away your jackets and sweaters for the season.

Unlike previous February storms that drew moisture from subtropical sources in a classic El Niño pattern, resulting in mild temperatures and high snow levels, this weekend’s weather systems originate from the Arctic, with high temperatures only reaching the 50s.

A potent cold front is expected on Saturday, accompanied by strong to gale-force (25 to 38 mph with gusts up to 50 mph) southwesterly winds along the coastline and mountain ridges on Saturday night into early Sunday morning.

Along with the winds, rain and the possibility of thunderstorms are forecast for Saturday into early Sunday morning. Rain will taper off into showers later on Sunday morning, ending by Sunday afternoon.

By Sunday morning, snow levels could plummet to as low as 3,000 feet, potentially dusting the higher peaks of San Luis Obispo and Santa Barbara counties with snow. In the Sierra Nevada, blizzard conditions are anticipated, with the Lake Tahoe region possibly receiving as much as 12 feet of snow.

Along the Central Coast, total rainfall amounts on Saturday into Sunday are forecast to range between 0.75 and 1.50 inches, with higher amounts in the coastal mountains on the Central Coast.

An upper-level trough will produce fresh to strong (19 to 31 mph) northwesterly winds, partly cloudy skies, and a few rain showers off the immediate coastline on Monday. Areas of dense ground fog are expected in the coastal and inland valleys during the overnight and morning. Overnight lows on Monday will reach the low 30s in the inland valleys (Paso Robles), the low 40s in the coastal valleys (San Luis Obispo), and along the coastline.

The northwesterly winds will decrease on Tuesday into Wednesday morning, with areas of marine low clouds developing along the coastline on Tuesday afternoon into Wednesday morning ahead of another cold front. This fast-moving cold front will produce strong to gale-force (25 to 38 mph with gusts to 45 mph) northwesterly winds and convective rain showers on Wednesday night into Thursday.

High temperatures on Thursday will only reach the mid to high 50s, and snow levels will drop to 4,000 feet. Total rainfall on Thursday is expected to range between 0.10 and 0.40 of an inch.

Dry, cool and breezy weather is expected from Friday into Saturday. Another low-pressure system is expected to create rain next Sunday and Monday.

Surf report

An 11- to 13-foot northwesterly (290-degree deep-water) swell (with a 14- to 16-second period) combined with 5- to 7-foot southwesterly seas are expected on Saturday into Sunday morning.

A 7- to 9-foot northwesterly (295-degree deep-water) sea and swell (with a 5- to 14-second period) will develop on Sunday afternoon, decreasing to 5- to 7-feet on Monday.

A 4- to 6-foot northwesterly (300-degree deep-water) swell (with an 8- to 11-second period) will develop on Tuesday, decreasing to 3- to 5-feet (with a 9- to 16-second period) on Wednesday morning.

Gale-force northwesterly winds will generate a 6- to 8-foot northwesterly (305-degree deep-water) sea and swell (with a 5- to 14-secod period) on Wednesday afternoon through Thursday, decreasing to 4- to 6-feet with the same period on Friday through Saturday.

Seawater temperatures: Much like last week, seawater temperatures will range between 57 and 59 degrees through next Sunday.

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 March 3, 2024 at 5:00 AM.