SLO County weather forecast for the week of March 7: Rain and maybe even some snow

After weeks of nearly dry weather in the heart of our rain season, the first significant rain since the end of January is expected this Tuesday and Wednesday.

Gentle to moderate (8 to 18 mph) Santa Lucia (northeasterly) winds on Sunday morning will produce mostly clear skies, except for areas of valley ground fog. Strong to gale-force (25 to 38 mph) northwesterly winds will follow on Sunday afternoon, decreasing Sunday night. High temperatures on Sunday will range from the high 50s to the low 60s along the beaches and mid-60s away from the coast.

Monday will be a transition day with moderate to fresh (13 to 24 mph) northwesterly winds, increasing mid to high-level clouds, and cooler temperatures.

A 1,007 millibar low-pressure system off the Northern California coastline will move southward later Monday through Thursday. This system will produce moderate to fresh (13 to 24 mph) southerly winds and rain by Tuesday afternoon, which will continue through Wednesday as this storm moves over San Luis Obispo and Santa Barbara counties.

This system will also bring a chance of isolated thunderstorms capable of heavy rainfall, gusty winds and lightning. At this time, between 0.75 and 1.50 inches of precipitation is expected from this system.

This tempest will bring the coolest temperatures on Tuesday and Wednesday, with highs only reaching the 50s as a cold air mass moves into Central California. Snow elevations are expected to drop to 3,000 and 3,500 feet and may fall even farther at times, especially overnight Tuesday and Wednesday.

A few rain showers will linger into Thursday morning, then gale-force northwesterly winds and partly cloudy weather will follow on Thursday afternoon through Friday. Warmer and more seasonable temperatures are favored to return by the end of the workweek, with dry conditions expected to continue through the following week.

Surf report

Strong to gale-force northwesterly winds will generate a 7- to 9-foot northwesterly (310-degree, deep-water) sea and swell (with a 5- to 13-second period) on Sunday, increasing to 8 to 10 feet (with a 7- to 17-second period) on Monday.

A 7- to 9-foot northwesterly (300-degree, deep-water) swell (with an 8- to 14-second period) is forecast along our coastline on Tuesday through Thursday, decreasing to 3 to 6 feet with same period by Friday and Saturday.

Seawater temperatures will range between 51 and 53 degrees through Saturday.

This week’s temperatures

LOWS AND HIGHS, PASO ROBLES

LOWS AND HIGHS, SAN LUIS OBISPO AND COASTAL VALLEYS

PG&E safety tip

The first rain after a dry period can challenge unprepared drivers with the unexpected loss of traction due to the accumulation of oils and foreign substances on the pavement. Please slow down and increase your following distance to allow time to react to other driver’s actions. Don’t forget California law requires you to have your headlights anytime the windshield wipers are operating continuously.

John Lindsey’s is PG&E’s Diablo Canyon marine meteorologist and a media relations representative. Email him at pgeweather@pge.com or follow him on Twitter @PGE_John.

This story was originally published March 7, 2021 at 5:00 AM.