SLO County will start the New Year chilly and windy. What’s next in the weather forecast?

This rain season, spanning July 1, 2024, to June 30, 2025, has followed a classic La Niña pattern, where the storm track shifts northward into Northern California, Oregon and Washington State.

Combined with well-below-normal rainfall this December, locations in San Luis Obispo and Santa Barbara counties have recorded well-below-average rainfall for this time of the year.

In fact, as you head further southward, rainfall averages decrease.

At Rocky Butte, rainfall reached 10.24 inches, which is 71% of the usual amount of rain for this time of year.

The Paso Robles Municipal Airport recorded 2.04 inches, 57% of the average. Moving south, the San Luis Obispo County Regional Airport received 2.92 inches, 51% of its usual 5.75 inches by the end of December.

Farther south, Santa Maria Airport measured 1.53 inches, just 40% of its average. The Santa Barbara Municipal Airport, meanwhile, has recorded only 0.64 inches, a mere 12% of the typical year end total.

Looking ahead, long-range forecasts indicate a dry start to January across much of Central California, further lowering rainfall percentages.

Gentle to moderate (8 to 18 mph) Santa Lucia (northeasterly) winds during the night and morning will produce dry and mild conditions with cool, crisp mornings and mild afternoons on Saturday.

Robust westerly winds in the mid and upper-level of the atmosphere will bring in variable amounts of mid to high level clouds throughout this week, creating some beautiful sunrises and sunsets.

The trailing edge of the cold front will bring increasing clouds and a few scattered light rain showers to the Central Coast on Sunday.

Rainfall amounts will remain below a tenth of an inch if your location receives any precipitation.

A 1,030 millibar high pressure system will develop over the Great Basin, creating strong gale-force (25 to 38 mph) and, at times, gusty Santa Lucia (northeasterly) winds on Monday into New Year’s Day.

The Santa Lucia winds will decrease to fresh to strong (19 to 31 mph) levels on Thursday.

Over this period, wind gusts could reach 60 mph in specific hot spots, including Highway 41 from Morro Bay High School toward Atascadero (about halfway up the hills), in the coastal canyons like Diablo Canyon and parts of eastern San Luis Obispo, including Cal Poly, San Luis Obispo High School and the French Hospital Medical Center.

This condition will produce bone-dry conditions in the coastal regions, however, areas of low clouds and fog are expected in the inland valleys with overnight temperatures dipping into the mid-30s (Paso Robles) and the mid-40s in coastal valleys (San Luis Obispo) and along the beaches.

We are at the time of the year when the coastal temperatures are warmer than the inland areas. Daytime highs will range from the high 60s to the low 70s in the coastal regions and the mid-60s in the inland locations.

The trailing edge of another cold front will move over the Central Coast on Friday with increasing clouds and a slight chance of a few light rain showers.

In the front’s wake, strong to gale force (25 to 38 mph) northwesterly winds and mostly clear skies will develop on Friday.

Another round of gusty Santa Lucia winds is expected next Saturday and Sunday.

For the following week, the American and European numerical model indicates dry weather through mid-January.

Surf report

A 10- to 12-foot northwesterly (290-degree deep water) swell (with a 15- to 17-second period) is expected along our coastline on Saturday, decreasing to 7- to 9-feet with the same period on Sunday.

A 6- to 8-foot northwesterly (295-degree deep water) swell (with a 12- to 14-second period) will develop along our coastline on Monday into Tuesday, decreasing to 4- to 6-feet (with an 11- to 16-second period) on Wednesday through Thursday.

Increasing northwesterly winds will generate a 7- to 9-foot northwesterly (305-degree deep water) sea and swell (with a 5- to 15-second period) Friday into next Saturday.

Surface seawater temperatures will range between 53 and 55 degrees through next Saturday and Sunday.

On this date in weather history (Dec. 29)

1830: A very heavy snowstorm ushered in the “winter of the deep snow.” The storm produced 30 inches of snow at Peoria, Illinois, and 36 inches at Kansas City, Missouri. Cold temperatures and snow continued until the middle of February, causing great suffering among pioneers. (David Ludlum)

1894: A severe freeze hit Florida, destroying fruit and causing considerable damage to trees. (David Ludlum)

1954: Fort Scott, Kansas, was buried under 26 inches of snow in 24 hours to establish a state record. (The Weather Channel)

2020: Readers reported 4.1 inches of rain in the Irish Hills during the day’s storm. Grover Beach (Guitar Man’s home) and Cayucos (John’s place) both recorded 1.23 inches of rain. Larry on Surf Street in Morro Bay reported 1 inch of rain.

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 December 29, 2024 at 5:00 AM with the headline "SLO County will start the New Year chilly and windy. What’s next in the weather forecast?."